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Lennox HP21 - Heat Pumps

1. HEAT PUMP SECTION 2B47 Supersedes Form No New Form No aia 528 897W _ 529 Litho U S A FIGURE 37 L THREE PHASE DEFROST SEQUENCE 3 Refer to the unit component section of this manual for detailed defrost control operation Defrost is terminated when relay K4 is de ener 1 When the defrost control determines a defrost needs to be initiated it gized closes an internal relay connected to DEF RLY terminal Relay 4 is energized Relay K4 controls defrost Thermostat Demand Satisfied 4 When thermostat demand is satisfied or if thermostat is switched OFF 2 When relay K4 energizes K4 1 switches to energize the reversing or switched to heating mode all outdoor unit operation stops after a valve K4 2 opens to de energize the outdoor fan and K4 3 closes to delay of 3 seconds TSC then completely resets erase accumulated energize auxiliary heat faults before cycling through the 5 minute timed off delay Page 39 21 2 3 Wiring Single Phase Units Shown 24V POWER s 5 i Al4 R HB FOR 621 HB DS FOR 621 54 CB CBH21 Parse DS ECON a BLOWER AUX HEAT AUX HEAT 2 NOTE ELECTRIC SHOCK HAZARD CAN CAUSE INJURY OR DEATH UNIT MUST BE GROUNDED IN ACCORDANCE WITH NATIONAL AND LOCAL CODES COOL HE
2. L e A 1 VOLTAGE FIELD INSTALLED L 9 e LOW VOLTAGE FIELD INSTALLED et valve reversing 1 plug two speed control R sensor ambient comp N FOR USE WITH COPPER contactor outdoor fan coniactor comp 2 speed thermostat room SCONETS switch limit hi press FOR MINIMUM CIRCUIT thermostat crankcase Fo X ihermostat service light DN UM e LM St S2 DENOTE SIOE 3 transformer cooling control TERMINAL COMPRESSOR MOTOR terminal strip low voltage DESIGNATIONS THERMALLY PROTECTED TERM BOX 2 LENNOX 2 m WIRING DIAGRAM HEAT PUMP OUTDOOR UNITS 21 415 1 A amp 3 HP21 513 1Y HP21 653 1Y 208 230 60 3 HEAT PUMP SECTION 2B47 Supersedes Form No aia 528 897W Litho U S A FIGURE 33 H THREE PHASE STARTING SEQUENCE defrost control CMC1 reversing valve L1 outdoor fan relay K10 speed control thermostat S55 service light thermostat S54 and ambi ent thermistor RT3 in outdoor unit 4 On power up 24VAC is fed through JP44 1 and JP44 7 to the TSC The TSC begins a 10 second power up delay 1 Line voltage feeds through L1 L2 and L3 to energize
3. Condenser fan and motor Wiring Drip loop FIGURE 4 H High Pressure Limit 54 All units are equipped with a high pressure limit mounted on the compressor discharge line The switch can be manual ly reset and has a cutout point of 410 10 psig The switch is electrically connected in series with crankcase thermo stat 540 in the two speed control s safety circuit When tripped the TSC interrupts unit operation If the high pres sure switch trips three times within the same thermostat demand the two speed control locks out and the contactor cannot energize Although the high pressure limit must be reset manually if the two speed control is locked out it must be reset before the unit can operate To reset the control break and re make thermostat demand Thermostat 540 Crankcase thermostat 540 is electrically connected se ries with high pressure limit S4 in the two speed control s safety circuit It is used in all units to monitor the tempera ture of the compressor The switch is a N C SPST belly band thermostat strapped to the compressor The switch is factory preset to trip at 190 F 5 F on a tem perature rise When tripped the TSC interrupts unit operation The crankcase thermostat automatically resets when the compressor crankcase drops below 110 F 7 F If the crankcase thermostat trips three times within the same thermostat demand the two speed control loc
4. por line is hotter than the liq uid line Stored liquid is heated boiled and forced back into circulation Stored Liquid To Liquid Line To be Circulated Through Indoor Coil Page 22 Vapor Line From Compressor Discharge Port FIGURE 20 HEATING MODE ro Vapor Line From Outdoor Coil Compensator Tank A During heating mode the va c por line is cooler than the liq uid line Excess refrigerant is forced into the charge com pensator where it condenses and collects Excess Refrigerant To be Condensed and Stored as Liquid ow Vapor Line To Compressor Suction Port K Service Valves The liquid line and vapor line service valves and gauge ports are accessible on the inside of the unit by removing the compressor access panel The one shot vapor line service valve figure 21 cannot be closed once it has been opened Both service valves are equipped with gauge ports which can be used for leak testing evacuating charg ing and checking charge A separate gauge port is provided for checking the suction pressure when the unit is in the heating cycle CAUTION When sweating any valve always wrap a wet rag around the valve and adjoining pipe Cool joint with wet rag after brazing WARNING The liquid line valve is not a back seat ing valve has valve core in service port and it should no
5. If the service light on the room thermostat is connected to the service relay the light will turn on if the control is in a lock out It will not turn on if the control is detecting non lock out problems In order for the service relay to indicate only a lock out condition one side of the relay must be wired to the alarm and the other side to Y2 During a simultaneous Y1 Y2 de mand with a non lock out condition the alarm will energize for a very short duration 2 seconds If both an alarm device and thermostat service lights are used an additional external relay may be required depending on thermostat used OPTIONAL INPUTS The control has two optional inputs for additional protection de vices If options 1 or 2 are going to be used move the three mini jumper to the YES side OPT 1 input will lock out the com pressor on the third count OPT 2 input will not lock out the compressor at any time but will display and store the problem code see Diagnostic code Table These inputs are designed for normally closed switches connected to 24VAC A CAUTION Do not remove the jumpers unless additional protection controls going to be installed If OPT 1 jumper is not connected to the NO pin the control will lock out the compressor If OPT 2 is not con nected to the NO pin the display only shows the problem code The unit wiring diagrams have been revised to reflect the changes for the HP21 4 5 TSC 6 and are s
6. DEFROST SEQUENCE Upon initial power up or first heating demand after cooling mode a sacrificial defrost operation will occur in order to cali brate the board Calibration will occur after accumulated com pressor run time of 34 minutes and coil temperature is below 35 13 Y1 is energized in HEAT mode de energizing reversing valve 14 Compressor run time of 34 minutes accumulated Defrost begins N C FAN terminal on board remains open allowing fan to cycle during defrost 15 Defrost will last a maximum of 14 minutes or until the coil temperature sensed at the coil probe exceeds the selected pin termination temperature Pin values are 50 60 70 and 80 Factory setting is 70 21 36 230 60 230 3 UNITS THREE PHASE 1 10 j 66 208 230 60 3 Woe AM AFTER 1 31 A ON ALL UNITS BUILT BEFORE CONTROL 554 W SERVICE LIGHT CONTROL IS EI BETWEEN L amp WI BETWEEN L YI ON TBI5 OR L TB AND C COMMON 24V POWER WIRE AN Hook up FOR UNITS WITH ORIGINAL THERMOSTATS CATALOG NUMBERS FOR ORIGINAL THERMOSTATS USED BEFORE 1 51 2000 ARE 51H3701 5IH4SO AND 21J7101 HEAT PUMP LENW Xe OUTDOOR UNITS NOTE FAN MOTOR ONLY REFER 10 UNIT RATING 0S ADLESS PLATE FOR MINIMUM CIRCUIT Meo ta 60 557 05 AMPACITY AND MAXIMUM OVER CURRENT LINE VOLTAGE FIELD INSTALLED PROTECTION SIZE CLASS VOLTAGE FIELD INSTALLED RNING DENOTES OPTIONAL
7. COM provides 24VAC Common 7 HLD Terminal Terminal HLD holds the internal timers in place be tween thermostat demands and allows the unit to continue timing upon resumption of thermostat de mand Terminal HLD is connected directly to 1st stage thermostat demand Page 18 WARNING AVOID CONTACT WITH OTHER CONTROL TERMINALS OR CONTROL COMPONENTS TO PLACE CONTROL IN TEST MODE NOTE Control will not go into test mode when discon nected from unit Unit load must be applied to control termi nals before the control will go into test mode 1 Make sure all control terminals are connected as shown on unit wiring diagram before attempting to place control in test mode See NOTE 2 Turn indoor thermostat to heat mode and adjust to high est temperature setting 3 With unit operating momentarily short across TEST pins as shown 4 LED should light and unit should operate in defrost mode for at least 30 seconds or until normal termination 5 To leave test mode momentarily short across TEST terminals again FIGURE 14 8 TEST Pins Each board is equipped with a set of test pins for use in troubleshooting the unit When momentarily shorted together these pins initiate a conventional defrost peri od Because the defrost period was initiated by momentarily shorting the two TEST pins the defrost period must last a minimum of 30 seconds see fig ure 14 A defrost initia
8. Outdoor Fan B4 START CAPACITOR C7 single phase only OUTDOOR FAN CAPACITOR C1 three phase only START RELAY K31 single phase oniy CONTACTOR K69 HP21 CONTROL BOX COMPONENTS DEFROST CONTROL TWO SPEED CONTROL CONTACTOR K1 CMC1 V i 21212 lolo A o TRANSFORMER T19 O 224 1 DUAL CAPACITOR C12 single phase EARLY HP21 1 2 3 SINGLE PHASE SERIES UNITS USE FAN CAPACITOR C1 AND COMPRESSOR CAPACITOR C5 IN PLACE OF DEFROST RELAY K4 ji f UN jl SPEED CONTROL 24V TERMINAL H THERMOSTAT 555 STRIP TB15 FIGURE 2 Contactor K1 Contactor K1 energizes low speed compressor operation in all units single phase and three phase In single phase units K1 is a two pole contactor with two sets of normally open contacts and in three phase units K1 is a five pole contactor with three sets of normally open contacts and two sets of normally closed contacts K1 is also equipped with a set of single pole double throw auxiliary contacts located on the side of the contactor The contactor is energized in response to low speed thermostat demand from two speed control jackplug J44 P44 pin 9 TABLE 2 Contactors Energized Single Phase Three Phase Low K1 K1
9. amp e BLOWER AUX HEAT AUX HEAT 2 COOL 2 REV VALVE COOL HEAT 1 BLACK COM DESCRIPTION COMPONENT control two speed compressor motor outdoor fan capacitor outdoor fan control defrost comp heater comp T jack two speed control contactor comp relay defrost COMMON e 9 e e AN LINE VOLTAGE FIELD INSTALLED L LOW VOLTAGE FIELD INSTALLED L2 666 6 666 RED 208V ORANGE 230V contactor outdoor fan contactor comp 2 speed valve reversing plug two speed control L3 R sensor ambient comp N FOR USE WITH COPPER thermostatsroom CONDUCTORS ONLY REFER switch limit hi press comp C TO UNIT RATING PLATE 22688 comp FOR MINIMUM CIRCUIT thermostat crankcase 9 0 9 emer E AMPACITY AND MAXIMUM ihermostat service light gt 3 e FUSE SIZE 5 thermostat speed control amp 0412 amp 3 3 12 JI 13 transformer cooling control COMPRESSOR MOTOR terminal strip low voltage THERMALLY PROTECTED TERM BOX 2 5 5 A 81 52 DENOTE LENNOX izies me WIRING DIAGRAM TERMINAL HEAT PUMP OUTDOOR UNITS DESIGNATIONS 21 415 1 gt lt 21 513 1 HP21 653 1Y 9 1 CMS 208 230 60 3 r CI
10. LENNOX vivir MFORMATIOM Corp 9434 L12 Revised 07 2007 Service Literature HP21 EARLY LATE MODEL HP21 SERIES UNITS INCLUDING TSC 2 TSC 3 AND TSC 6 The HP21 is a high efficiency residential split system heat pump with a two speed compressor Early models include HP21 411 511 and 651 Late models built after March 1 2000 include HP21 36 48 and 60 All models are avail able in sizes ranging from 3 through 5 tons in either single or three phase configuration Early and late models feature solid state two speed control and new solid state demand defrost control The two speed control regulates compres sor speed in response to thermostat demand during cooling mode Compressor speed is regulated by outdoor air temperature during heating mode The defrost control monitors outdoor air temperature and liquid line tempera ture to determine when defrost is needed The series uses conventional heat pump circuitry with expansion valves in the outdoor and indoor units This manual is divided into sections which discuss the com ponents refrigerant system charging procedures maintenance and operation sequences All specifications in this manual are subject to change DANGER Electric Shock Hazard cause injury death Line voltage is present at all compo nents when unit is not in operation on units with single pole contactors Disconnect all remote electrical power supplies before opening unit panel Un
11. ter code is displayed the low pressure switch stops operation low pressure is auto reset Check for low sys tem charge Code 6 Hot Compressor lt Five Minutes Code 6 indicates the compressor temperature exceed ed its limit after running less than five minutes Code 6 is stored Page 14 TABLE 8 TSC 6 DIAGNOSTICS CODES DISPLAY LIGHTS CODE NUMBER CONDITION 1 Power loss for two OFF OFF OFF fie cycles Input Indication Unsteady Input ON ON Pressure Switch Open OFF OFF OFF lt 2 minutes Pressure Switch Open OFF OFF gt 2 minutes Hot Compressor lt 5 OFF Mie min or open sensor Hot Compressor gt 5 min FF Me or open sensor Option 1 lt 5 minutes F OFF Option 1 gt 5 minutes Option 2 Open Compressor Temp Sensor Problem Outdoor temperature Sensor Not Used Test Mode No Jumper in place Indication Code 7 Hot Compressor gt Five Minutes Code 7 indicates the compressor temperature exceeded its limit after running more than five minutes Code 7 is stored Code 8 Option 1 lt Five Minutes Code 8 occurs if the Option 1 safety device switch opens af ter the compressor runs less than five minutes Code 8 is stored Code 9 Option 1 gt Five Minutes Code 9 occurs if the Option 1 safety device switch opens after the compressor runs more than five minutes Code 9 is stored Code 10 Option 2 Code 10 is displayed if th
12. 6 Check for correct voltage at unit 7 Check amp draw on blower motor does not apply to CB21 Unit nameplate Actual VI Miscellaneous If the fan orifice should ever need to be removed for ser vice make sure the control box seals watertight before placing the unit back in service Figure 23 shows the com ponents used to make the control box watertight Two screws securing the top of the control box to the cabinet must have rubber washers installed Also the control box must be installed with a foam rubber weatherstrip installed along the top edge between the control box and the cabi net HP21 CONTROL BOX WEATHERPROOFING SCREWS WITH RUBBER WASH ERS WASHERS PREVENT WATER FROM DRIPPING INTO CONTROL AREA MAKE SURE WASHERS ARE IN GOOD CONDITION AND MAKE SURE SCREWS SEAT SECURELY AND ARE NOT CROSS THREADED WEATHERSTRIPPING BETWEEN CONTROL BOX AND FAN ORIFICE PANEL USED TO PREVENT FAN FROM THROWING WATER INTO CONTROL BOX FIGURE 23 Page 26 VII WIRING DIAGRAMS AND OPERATION SEQUENCE A Field Wiring FIELD WIRING DIAGRAM HP21 WITH CB21 EM HT RELAY 24VAC 18GA MIN THREE PHASE LINE VOLTAGE An 1 LOW VOLTAGE FIELD INSTALLED HEED WIRING 1 NEC CEC CLASS 2 NOTE ALL REMAINING WIRES 208 230 60 3 FACTORY INSTALLED 131214 GROUND N COMPRESSOR S THERMOSTAT CONTACTOR a USE COPPER CONDUCTOR ONLY SING
13. HIGH SPEED START WINDINGS LOW SPEED START WINDINGS FIGURE 26 THREE PHASE MOTOR WINDINGS LOW SPEED SERIES DELTA CIRCUIT L1 T1 START RELAY THREE PHASE MOTOR WINDINGS HIGH SPEED PARALLEL DELTA CIRCUIT 74 COMPRESSOR 1 1 FIGURE 27 24V POWER 9 BLOWER AUX HEAT AUX HEAT 2 COOL HEAT 2 REV VALVE COOL HEAT_ 6060 BLACK COM DESCRIPTION COMPONENT control two speed compressor motor outdoor fan capacitor outdoor fan capacitor compressor capacitor comp hard start control defrost comp X heater comp EQUIP jack two speed control GROUND i contactor comp COMMON relay defrost relay hard start L2 e contactor comp 2 speed valve reversing plug two speed control T resistor bleed sensor ambient comp ihermostat room 000 RED 208V ORANGE 230V O switch limit hi press comp N FOR USE WITH COP thermestat crankcase REFER TO UNIT Mime 9 CIRCUI 3 terminal
14. ALLOW 1 MINUTE FOR THE UNIT TO START DOES UNIT START AND RUN HIGH SPEED ves LLL wo gt coro ON NEXT PAGE IS UNIT IN COOLING MODE REVERSING VALVE SHOULD BE ENERGIZED REVERSING VALVE ENERGIZED YES d NO CHECK VOLTAGE ACROSS TERMINALS R AND X AT UNIT LOW VOLTAGE TERMINAL STRIP TB15 IS VOLTAGE 24 6VAC YES o NO CHECK REVERSING VALVE FOR MALFUNCTIONS REPLACE IF NECESSARY REPEAT TROUBLESHOOTING PROCEDURE HIGH SPEED COOLING O K LOW SPEED COOLING TURN INDOOR THERMOSTAT TO OFF POSITION DISCONNECT THERMOSTAT WIRE FROM TERMINAL Y2 OF HEAT PUMP LOW VOLTAGE TERMINAL STRIP TB15 SET INDOOR THERMOSTAT TO LOWEST TEMPERATURE SETTING TURN INDOOR THERMOSTAT TO COOL MODE IF POWER TO OUTDOOR UNIT HAS BEEN OFF WAIT AT LEAST 10 SECONDS TO ALLOW TSC TO POWER UP PUSH AND RELEASE THE OVERRIDE BUTTON ON THE TSC TO BY PASS THE 5 MINUTE TIMED OFF DELAY ALLOW 1 MINUTE FOR THE UNIT TO START DOES UNIT START AND RUN ON LOW SPEED r YES a ENSE NO i GO TO B IS UNIT IN COOLING MODE ON NEXT PAGE REVERSING VALVE SHOULD BE ENERGIZED REVERSING VALVE ENERGIZED r YES EE PER NO LOW SPEED COOLING O K TSC OPERATING PROPERLY REASSEMBLE UNIT Page 51 CHECK INDOOR THERMOSTAT FOR MALFUNCTIONS REPLACE IF NECESSARY HIGH SPEED HEATING 1 TURN INDOOR THERMOSTAT TO OFF POSITION 2 PLACE A JUMPER WIRE ACROSS SPEED CONTROL THERMOSTAT 555 INOUTDOOR UNIT 3 SET INDOOR THERMOSTAT TO HIGHEST TEMPE
15. B ON PREVIOUS PAGE CHECK VOLTAGE ACROSS TERMINALS Y1 AND X AT UNIT LOW VOLTAGE TERMINAL STRIP TB15 IS VOLTAGE 24 6 YES _ _ CHECK INDOOR THERMOSTAT FOR MALFUNCTIONS REPLACE IF NECESSARY CHECK VOLTAGE AT CONTACTOR COILS FOR SINGLE PHASE UNITS K69 ONLY SHOULD BE ENERGIZED FOR THREE PHASE UNITS K1 ONLY SHOULD BE ENERGIZED IS VOLTAGE 24 6VAC NO YES TROUBLESHOOTING PROCEDURE IS CONTACTOR S COIL ENERGIZED NO L YES ARE CONTACTS CLOSING CHECK SECONDARY OUTPUT VOLTAGE OF THE TRANSFORMER IN THE OUTDOOR UNIT IS VOLTAGE 24 6VAC NO u YES 7 IS FUSE PROVIDED IN TRANS FORMER SECONDARY NO _ YES 7 IS FUSE NO YES NO REPLACE CONTACTOR YES TROUBLESHOOTING PROCEDURE CHECK STARTING CIRCUIT AND REPLACE COMPRESSOR FUSE REPAIR OR REPLACE AS NECESSARY TROUBLESHOOTING PROCEDURE REPEAT TROUBLESHOOTING TURN OFF POWER TO INDOOR AND OUTDOOR PROCEDURE UNITS DISCONNECT JACKPLUG JP44 FROM TSC TURN ON POWER TO OUTDOOR UNIT CHECK VOLTAGE ACROSS TERMINALS 2 AND 7 OF JACKPLUG JP44 15 VOLTAGE 24 6 CHECK PRIMARY INPUT VOLTAGE OF THE TRANSFORMER IN THE OUTDOOR UNIT IS MEASURED VOLTAGE SAME AS VOLTAGE ON UNITS RATING PLATE CHECK SWITCHES 54 AND 540 FOR MALFUNCTIONS REPLACE IF NECESSARY YES NO REPLACE TRANSFORMER CHECK LINE VOLTAGE WIRING REPEAT TROUBLESHOOTING P
16. LOW VOLTAGE FIELD INSTALLED FOR USE WITH COPPER CONDUCTORS ONLY REFER TO UNIT RATING PLATE FOR MINIMUM CIRCUIT AMPACITY AND MAXIMUM FUSE SIZE COMPRESSOR MOTOR THERMALLY PROTECTED TERM BOX contactor comp K4 l 2 S relay defrost COMMON 1 contactor outdoor fan K69 1 2 contactor comp 2 speed LI valve reversing 1 P44 plug two speed control RTS sensor ambient comp 51 thermostat room 54 switch limit hi press comp S40 thermostat crankcase 554 ihermostat service light 555 thermostat speed control T19 transformer cooling control terminal strip low voltage TERMINAL HEAT PUMP OUTDOOR UNITS DESIGNATIONS 2 WIRING DIAGRAM 81 82 DENOTE amp 21 515 1 21 655 1 208 250 60 5 21 415 1 HEAT PUMP SECTION 2B47 Supersedes Form No New Form No 8 897W 529 Litho U S A FIGURE 36 K THREE PHASE HEATING SEQUENCE 1 Speed control thermostat S55 determines whether the compressor is to operate on high or low speed based on outdoor temperature If out door temperature drops below set temperature 555 closes to shunt across Y2 When Y2 is shunted a 2nd stage demand is sent to the two speed control and
17. O TB15 Y2 energizes TSC terminal JP44 4 TB15 Y1 energizes TSC terminal JP44 6 6 TSC delays 3 seconds before responding 7 If the unit is changing from 1st stage to 2nd stage demand the TSC initiates speed change delay and de energizes JP44 8 and JP44 9 to stop all unit operation for 60 5 sec onds After TSC completes the 60 5 second speed change delay or if the unit is starting up in 2nd stage directly from OFF mode TSC checks safety circuits by looking for 24VAC at JP44 7 and by checking resistance through wires con nected to S1 and 52 8 If all safety circuits check out TSC energizes K1 and K69 Compressor begins high speed startup 9 When thermostat demand is satisfied or if thermostat is Switched OFF or switched to heating mode all outdoor unit operation stops after a delay of 3 seconds TSC then com pletely resets erase accumulated faults before beginning a 5 minute timed off delay Page 49 THREE PHASE HEATING SEQUENCE 10 1st stage demand energizes TB15 Y1 TB15 Y1 energizes TSC and defrost control Defrost control initializes timing sequence NOTE 2nd stage heating demand may be energized di rectly without passing through 1st stage 11 TSC delays 3 seconds before responding to the new com mand Then compressor begins operating at low or high speed depending on the outdoor ambient 12 2nd stage heating demand energizes TB15 Y1 and TB15 W1 TB15 Y1 energizes TSC The compressor con tinues to operate
18. REV VALVE COOL HEAT 666 666 BLACK COM 666 DESCRIPTION COMPONENT control two speed compressor motor outdoor fan capacitor outdoor fan control defrost comp heater comp RED 208V ORANGE 230V X jack two speed control EQUIP contactor comp COMMON relay defrost GROUND LINE VOLTAGE FIELD INSTALLED LOW VOLTAGE FIELD INSTALLED contactor outdoor fan contactor comp 2 speed valve reversing plug two speed control 51 52 DENOTE N FOR USE WITH COPPER fe sensor atpient come TERMINAL DES CONDUCTORS ONLY REFER ae oe IGNATIONS switch limit hi press comp 3 G TO UNIT RATING PLATE m i FOR MINIMUM CIRCUIT ermostat crankcase T T2 AND MAXIMUM thermostai service light FUSE SIZE S fhermostai speed control 413 t 3 transformer cooling control A COMPRESSOR MOTOR terminal strip low voltage TERW BOX THERMALLY PROTECTED 2 LENNOX 2 nc WIRING DIAGRAM 5 90 HEAT PUMP OUTDOOR UNITS z 21 415 1 21 515 1 21 655 1 EP dee 208 230 60 3
19. VALVE COOL HEAT BLACK COM RED 208V ORANGE 230V EQUIP GROUND 6 660 DESCRIPTION COMPONENT control two speed compressor motor outdoor fan capacitor outdoor fan capaci tor compressor capacitor comp hard start control defrost comp X jack two speed contro contactor comp AN LI eC L2 e FOR USE WITH COPPER CONDUCTORS ONLY REFER TO UNIT RATING PLATE FOR MINIMUM heater comp COMMON relay defrost relay hard start contactor comp 2 speed valve reversing plug two speed control resistor bleed Sensor ambient comp thermostat room switch limit hi press thermostat crankcase thermostat service ight thermostat speed control transformer cooling control CIRCUIT AMPACITY AND MAXIMUM FUSE SIZE COMPRESSOR MOTOR THERMALLY PROTECTED A 51 52 DENOTES TERMINAL HI SPEED DESIGNATIONS START WINDING LO SPEED START WINDING LINE VOLTAGE FIELD INSTALLED LOW VOLTAGE FIELD INSTALLED TERM BOX Al4 terminal strip low voltage LENNOX nc WIRING DIAGRAM HEAT PUMP OUTDOOR UNITS 21 4
20. WIRIING LENNOX 2 WIRING DIAGRAM 7 94 HI SPEED i i START HEAT PUMP OUTDOOR UNITS LO SPEED HP21 411 511 651 4 5 P START WINDING 208 230 60 1 TERM BOX HEAT PUMP SECTION 2B46 Supersedes Form No New Form No 9 811 551 82W 1994 Lennox Industries Inc Litho U S A 21 4 5 Wiring Three Phase Units Shown 24V POWER 2 HB FOR 621 DS 21 ECON NOTE ELECTRIC SHOCK HAZARD CAN CAUSE INJURY OR DEATH UNIT MUST BE GROUNDED IN ACCORDANCE WITH NATIONAL AND LOCAL CODES aL COOL HEAT 2 p VALVE __ rp COOLZHEAT 0 5 OPTIONAL COMPONENTS A FOR USE WITH COOPER CONDUCTORS ONLY REFER TO UNIT RATING PLATE FOR MINIMUM CIRCUIT AMPACITY AND MAXIMUM FUSE SIZE COMPRESSOR MOTOR THERMALLY PROTECTED A P3 HOOKUP WITH WHITE RODGERS OR HEATCRAFT ELECTRONIC THERMOSTAT KIO 554 OR RT3 HOOKUP WITH A OR HONEYWELL THERMOSTAT BLACK COM KEY COMPONEN a ET A Co 4 CONTROL TWO SPEED BI COMPRESSOR MOTOR OUTDOOR FAN 1 A CAPACITOR OUTDOOR FAN I RT3 CONTROL DEFROST COMPRESSOR HEATER
21. a second even if the problem condition no longer exists If other prob lems occur during a lock out condition the codes for those problems will be saved in memory but not displayed The stored problem codes are displayed by recalling them from memory The diagnostic codes can be re displayed by setting the jumper to the recall position The stored codes are dis played by pushing the push button As previously mentioned the push button is used to bypass the five minute delay and to initiate the test mode In addition the button is used to step back through the stored diagnostic codes and erase the diag nostic code memory Diagnostic codes are recalled in the reverse order of actual occurrence Each subsequent button push will display additional codes until the last one which will stay on with additional button pushes Hold the button down until the lights go off approximately five seconds to erase the memory The control has a nonvolatile memory that stores the 63 most recent diagnostic codes These codes are stored in memory even in the event of a power loss Not all codes cause lock outs or indicate problems The pur pose of the diagnostic lights is to let the installer or service technician know what is going on with the entire system not just the two speed control Some codes do indicate malfunc tions or problems with either the control or the HP21 while others inform the technician of the unit s status All codes ex cept for
22. and all tools on an unpainted unit surface before performing any service procedure TSC 2 Two Speed Control The TSC two speed control figure 5 a Lennox built con trol designed for use with two speed condensing units and heat pumps The control provides automatic switching from low speed to high speed operation and back The TSC 2 is designed for use with Bristol and Copeland com pressors 21 series units use Copeland compressors All early model HP21 1 units use the TSC 2 controls The TSC two speed control contains relays which energize compressor operation in response to thermostat demand High speed operation can be energized and de energized without passing through low speed The control also con tains safety timed off delays compressor over temperature sensing which help protect the compres sor Page 6 TSC 2 TWO SPEED CONTROL 51 52 TO COMPRESSOR WINDING TEMPERATURE SENSORS 51 MANUAL OVERRIDE OF 5 MINUTE DELAY RED DIAGNOSTIC LED 24VAC POWER INPUT 24VAC NEUTRAL GROUND NOT USED 2nd STAGE THERMOSTAT DEMAND THERMOSTAT COMMON C 1st STAGE THERMOSTAT DEMAND 24VAC FROM SAFETY SWITCHES TO INTERNAL CONTACTOR COIL INPUT HIGH SPEED 24VAC OUTPUT LOW SPEED 24VAC INPUT FIGURE 5 A timed off delay in the control prevents the compressor from operating for five minutes after the end of a thermostat demand or after a power failure to prevent short cycling see miscellaneous
23. begins start up K31 remains de energized during compressor start up and the start capacitor C7 remains in the circuit As the compres sor gains speed K31 is energized by electromotive forces generated by the compressor When K31 energizes its con tacts open to take the start capacitor out of the circuit E Terminal Strip TB15 All HP21 units are equipped with a low voltage terminal strip located in the unit control box for making up thermo stat wiring connections refer to figure 2 F Compressor B1 See ELECTRICAL DATA or compressor nameplate for specifications Figure 3 shows the compressor terminal box All compressors are equipped with internal pressure relief valves set at 450 50 psig Compressors in all units use insertion type crankcase heaters which are regulated by relays in the 21 TYPICAL TWO SPEED COMPRESSOR TERMINAL BOX COPELAND SINGLE PHASE SHOWN 8 T7 TAO FIGURE 3 G Outdoor Fan Motor B4 The specifications table on page 1 of this manual shows the specifications of outdoor fans used in all HP21 units In single phase units the outdoor fan is controlled by the compressor contactor and is de energized when the de Page 5 frost relay is energized In three phase units the outdoor fan is controlled by contactor K10 and is de energized when the defrost relay is energized See figure 4 if outdoor fan motor replacment is necessary FAN GUARD
24. compressor operation and which cause the compressor to shut off are counted After a fault is counted the control stops unit operation resets and begins a five minute time delay step 2 operation se quence If the control senses a fault at the end of five minutes the unit will not restart If the control counts three faults during the same thermostat demand the control locks out unit operation NOTE If the control locks out it can be reset by break ing thermostat demand for about five seconds then remaking thermostat demand Also anytime thermo stat demand is removed or power is interrupted the control resets to zero faults A fault occurs when 1 Compressor operation is monitored by high pressure switch and crankcase temperature thermostat These controls are wired in series If either one trips com pressor operation is interrupted and one fault is counted High pressure switch must be reset manually but crankcase temperature switch resets automatical ly IMPORTANT If the cycle counter counts three faults during the same thermostat demand the control locks out The outdoor unit remains inoperable until thermo Stat demand is broken This indicates further troubleshooting is needed Though the control can be reset by breaking thermostat demand the unit may re main inoperable The high pressure or high temperature conditions may still exist and must be lo cated and corrected before the unit can be placed back in servi
25. de energize the crankcase heater All other K1 contacts close to start outdoor fan operation and to begin compressor low speed start up 3 Compressor B1 terminal 1 and the outdoor fan circuit are energized by K1 contacts L1 T1 Compressor terminal 7 is energized by contactor K1 terminal L2 T2 through contactor K69 terminal T1 X1 Compressor terminal 8 start winding is energized by contactor K1 terminal L2 T2 through the start C7 and run C5 capacitors and contactor K69 termi nal T3 X3 4 Outdoor fan B4 is energized through relay K4 2 when contactor K1 contacts L1 T1 and L2 T2 close 5 As the compressor nears full speed potential relay K31 energizes and K31 contacts open to de energize the start capacitor HIGH SPEED 6 2nd stage demand If all safety circuits check out TSC energizes JP44 8 7 Contactor K69 energizes and K69 2 auxiliary contacts close to ener gize contactor K1 K1 2 auxiliary contacts open to de energize the crankcase heater All other K1 contacts close K1 contacts 11 1 Tous L2 T2 and L3 T3 close while contacts T1 X1 and T3 X3 open GROUND BLACK COM RED 208V ORANGE 230V 8 Compressor B1 terminal 3 start winding is energized by contactor K1 T A terminal L2 T2 through the start C7 and the run C5 capacitors and _ through contactor K69 terminal L3 T3 Compressor terminal 2 is ener gized by contactor K1 terminal L2 T2 Compressor terminal 1 is energi
26. section The control also counts unit fault conditions Whenever the compressor stops due to a safety limit trip or if the compressor winding temperature becomes too hot the control s internal cycle counter accu mulates one fault If three unit faults are counted during the same thermostat demand the control locks out and stops all unit operation The control can be reset by breaking and remaking thermostat demand Also unit faults are erased when power is interrupted When thermostat demand changes stages compressor operation stops for approxi mately one minute to allow refrigerant pressure to equalize in the system In order to aid servicing and troubleshooting a manual override button has been placed on the control The manu al override button when pressed and released bypasses the five minute delay so low speed or high speed operation can be immediately energized A red LED located on the face of the control can be used for diagnostics The control continually self tests its internal circuits and uses the diagnostic LED to indicate control fail ure or Safety Dormant Lockout A Safety Dormant Lockout is caused by abnormal line voltage such as a lightning strike near the unit Page 7 Sf U 10 TOP VIEW Normal Operation Sequence General Operation On power up the control begins a ten second initial power up delay The control then begins a five minute delay during
27. set and indoor coil to 150 psig 3 Check lines and connections for leaks NOTE If electronic leak detector is used add a trace of refrigerant to the nitrogen for detection by the leak de tector 4 Release nitrogen pressure from the system correct any leaks and recheck B Evacuating and Dehydrating the System 1 Attach gauge manifold as shown in figure 16 Connect vacuum pump with vacuum gauge to center port of gauge manifold With both manifold service valves open start pump and evacuate indoor coil and refriger ant lines NOTE A temperature vacuum gauge mercury vacuum U tube or thermocouple gauge should be used The usual Bourbon tube gauges are not accurate enough in the vacuum range 2 Evacuate the system to 29 inches vacuum During the early stages of evacuation it is desirable to stop the vacuum pump at least once to determine if there is a rapid loss of vacuum A rapid loss of vacuum would indi cate a leak in the system and a repeat of the leak testing section would be necessary After system has been evacuated to 29 inches 737mm close gauge manifold valves to center port stop vacuum pump and disconnect from gauge man ifold Attach an upright nitrogen drum to center port of gauge manifold and open drum valve slightly to purge line at manifold Break vacuum in system with nitrogen pressure by opening manifold high pressure valve Close manifold high pressure valve to center port Close nitrogen drum valve an
28. temperature TABLE 16 Liquid Temp Minus Am bient Temp F a ee NCC NN 21 411 413 21 36 230 233 21 511 513 21 48 230 233 21 651 653 21 60 230 233 BLOCKING OUTDOOR OUTDOOR COIL SHOULD BE BLOCKED ONE SIDE AT A TIME WITH CARD BOARD OR PLASTIC SHEET UNTIL PROPER TESTING PRESSURES ARE REACHED CARDBOARD OR PLASTIC SHEET FIGURE 22 OUTDOOR TEMPERATURE BELOW 60 F steps 6 through 8 6 It is not recommended that the system be charged be low 60 F If charging below 60 F is required the most reliable method is to weigh in the charge listed on the unit nameplate This amount table 14 will be correct for a system with a line set of 25 feet If line set is longer or shorter than 25 feet add or remove refrigerant as shown in table 15 7 If ambient temperature is less than 60 F 10 sys tem should be charged using the subcooling method Air flow will need to be restricted to achieve pressures in the 200 250 psig range See figure 22 These high er pressures are necessary for checking the subcooling temperature Block equal sections of air in take panels moving obstructions sideways as shown until liquid pressure rises above 200 psig 1 Read liquid line pressure from gauge and convert to condensing temperature using standard R 22 temper ature pressure conversion chart or conversion scale on gauge The difference between the liquid line tem
29. three are stored in memory and may be recalled Code 1 Power Loss for Two Electrical Cycles This code indicates that the unit s power skipped two elec trical cycles 33 40 milliseconds It may suggest that power to the unit is dirty or is of low quality Code 1 is stored Code 2 Input Indication This code indicates that a change has been made and that the control acknowledges the change It does not in dicate a problem condition It indicates activity such as jumper setting changes delay overrides or addition of an optional safety device to Option 1 or 2 Code 2 is not stored Code 3 Unsteady Thermostat Input Code 3 indicates intermittent inputs from the room ther mostat Most likely there is a loose connection at the thermostat when this condition appears Code 3 is stored Code 4 Pressure Switch Opens lt Two Minutes If the low or high pressure switch opens after the compressor has run for less than two minutes Code 4 will be displayed This may indicate blockage or fan failure Code 4 is stored If the unit still operates after code is displayed the low pressure switch stops operation low pressure is auto reset Check for low system charge Code 5 Pressure Switch Opens gt Two Minutes If the low or high pressure switch opens after the com pressor has run for more than two minutes Code 5 is displayed This may indicate an improper charge or coil obstruction Code 5 is stored If the unit still operates af
30. which the unit is not operational control and outdoor unit do not respond to thermostat demand Once the five minute delay is complete the control waits in OFF mode for thermostat demand After receiving a thermostat demand the TSC delays three seconds before responding Low speed demand JP44 6 energizes low speed op eration JP44 9 OR high speed demand JP44 4 energizes high speed operation JP44 8 During unit operation if low speed demand changes to high speed demand or if high speed demand changes to low speed the control delays three seconds before responding Then all unit operation stops for 60 5 seconds control de energizes JP44 8 and JP44 9 This allows refrigerant pressure to equalize in the sys tem At the end of the 60 5 second delay the control responds to whatever thermostat demand is present If no thermostat demand is present the control resets see unit fault conditions section and the control re turns to step 2 above If thermostat demand stops compressor operation all unit operation stops after a three second delay control de energizes JP44 8 and JP44 9 the control resets see unit fault conditions section and the control re turns to step two Two Speed Control Fault Conditions If the control is in low speed operation high speed opera tion OFF mode or speed change delay the control counts or accumulates faults on an internal cycle counter Only faults which occur during
31. 11 1 21 511 1 21 651 208 250 60 1 HEAT PUMP SECTION 2B46 Super edes Form No New Form No 28 896W 529 20W Litho U S A FIGURE 30 E SINGLE PHASE COOLING SEQUENCE 1 1st stage cooling demand energizes TB15 Y1 and TB15 O TB15 O energizes reversing valve 11 15 1 energizes TSC terminal JP44 6 and defrost control terminal HOLD Defrost control begins ini tial timing sequence NOTE 2nd stage cooling demand may be energized directly without passing through 1st stage 2 TSC delays 3 seconds before responding to the new command 3 If the unit is changing from 2nd stage to 1st stage demand TSC initi ates speed change delay and de energizes JP44 8 and JP44 9 to stop all unit operation for 60 5 seconds After TSC completes the 60 5 sec ond speed change delay or if the unit is starting up in 1st stage directly from OFF mode TSC checks safety circuits by looking for 24VAC at JP44 7 and by checking resistance through wires connected to S1 and 52 4 If all safety circuits check out TSC energizes 1 and compressor gins low speed startup 5 2nd stage cooling demand energizes 15 1 15 2 and TB15 O TB15 O energizes TSC terminal JP44 4 TB15 O energizes TSC ter minal JP44 6 and defrost control terminal HOLD 6 TSC delays 3 seconds before responding 7 If the unit is changing from 1st stage to 2nd stage demand the TSC initiates speed change delay and de e
32. 3 HP21 653 HP21 36 230 233 HP21 60 230 233 HP21 48 230 233 Ambient Temperature F 34 and above When the lockout time as shown in table 11 is satisfied the control begins to compare the temperature difference be tween the liquid line and ambient air Liquid line temperature and ambient air temperature are monitored in definitely total run time continues to accumulate When the actual temperature difference between liquid line and ambient air exceeds a calculated temperature difference the defrost relay is activated Table 12 shows how the de frost control calculates the difference Defrost will last for for a maximum of 15 minutes or until coil temperature reaches 70 F An LED on the circuit board in dicates control is in defrost mode Defrost timings are not adjustable When defrost relay contacts close compressor total run time and lockout time are cleared When defrost terminates timing cycles restart If thermostat demand is satisfied and a defrost was not initi ated during the cycle compressor run time will stop but not reset when demand is satisfied and continue when a new thermostat demand is received If the control accumu lates a total compressor run time of six hours defrost will be initiated Cooling Mode Operation The defrost control uses the liquid line temperature sensor to determine that the control is in cooling mode and defrost is no longer needed When the liquid line rises above 65 F the defr
33. 69 High speed demand de energizes K1 and energizes contactor K69 K69 locks out K1 and energizes the compressor on high speed K1 is wired so that when de energized the contactor forms a parallel common connection to the motor windings for high speed forming a parallel Delta connection for Cope land compressors When K1 is energized the contactor forms a series Delta connection to the compressor wind ings Refer to operation sequence in back of this manual for more information C Defrost Relay K4 All HP21 units are equipped with a defrost relay located in the unit control box which controls defrost The relay is a 3PDT relay powered 24 VAC from the thermostat K4 is enabled during both cooling and heating modes except emergency heat It is only powered when the defrost control is calling for defrost When energized the revers ing valve and indoor auxiliary heat are energized Simultaneously the outdoor fan is de energized K4 latches in for the duration of the defrost period Page4 D Hard Start Relay K31 single phase only All single phase HP21 units are equipped with a hard start relay located in the unit control box which controls the op eration of the compressor starting circuit The relay is normally closed when the compressor contactor K1 is de energized Capacitor C7 is connected in series to a set of normally closed K31 contacts and assists the compressor in starting When 1 energizes the compressor immediately
34. AT 2 REV_VALVE lot COOL HEAT 3 DENOTES OPTIONAL COMPONENTS A S54 HOOKUP WITH WHITE RODGERS OR HEATCRAFT ELECTRONIC THERMOSTAT N S54 amp HOOKUP WITH GE OR HONEYWELL THERMOSTAT DESCRIPTION KEY COMPONENT Al4 CONTROL TWO SPEED BI COMPRESSOR B4 MOTOR OUTDOOR FAN CI CAPACITOR OUTDOOR FAN C5 CAPACITOR COMPRESSOR C7 CAPACITOR COMP HARD START CMCI CONTROL DEFROST COMPRESSOR HRI HEATER COMPRESSOR J44 JACK TWO SPEED CONTROL Kl l1 2 CONTACTOR COMPRESSOR K4 1 2 3IRELAY DEFROST K3I RELAY HARD START BLACK COM RED 208V ORANGE 230V x lt E z amp 3 x 2 Q Q lt PLACE TO BLOWWER OR FURNACE DIAGRAM 24V COMMON K58 1 RELAY LOW AMBIENT K69 1 2 CONTACTOR COMPRESSOR TWO SPEED N FOR USE WITH COPPER VALVE REVERSING CONDUCTORS ONLY P44 PLUG TWO SPEED CONTROL REFER TO UNIT RATING R21 RESISTOR BLEED PLATE FOR MINIMUM ANIRT3 SENSOR AMBIENT COMPENSATION CIRCUIT AMPACITY S4 SWITCH LIMIT HI PRESS COMP 1 AND MAXIMUM FUSE SIZE SI SWITCH LOW PRESS LOW AMB A 540 THERMOSTAT CRANKCASE COMPRESSOR MOTOR 554 THERMOSTAT SERVICE LIGHT THERMALLY PROTECTED TI9 TRANSFORMER COOLING CONTROL TBIS TERMINAL STRIP LOW VOLTAGE LINE VOLTAGE FIELD INSTALLED CLASS II VOLTAGE FIELD
35. AT HIGH PRESSURE SWITCH OUTDOOR FAN MOTOR LEADED AN OUTDOOR FAN MOTOR LEADLESS SERVICE THERMOSTAT EQUIPMENT GROUND OUTDOOR FAN MOTOR LEADED OUTDOOR FAN MOTOR LEADLESS LINE VOLTAGE FIELD INSTALLED e CLASS VOLTAGE FIELD INSTALLED HP21 36 233 60 233 Wiring 9 CONTACTOR SI ROOM THERMOSTAT ORANGE EM HT RED SERV C D vos DEFROST CONTROL J 1 1 SOURCE 20 VA MINIMUM NEC CLASS 2 TO BLOWER RELAY IN INDOOR UNIT TO EMERGENCY HEAT RELAY AFTER 31 2000 SERVICE LIGHT CONTROL A ON ALL UNITS BUILT BEFORE 1 31 2000 S54 WILL BE WIRED BETWEEN L AND WI SERVICE LIGHT CONTROL IS EITHER WIRED ON TBIS BETWEEN L AND YI ON TBIS OR L TBIS AND C COMMON 24V POWER WIRE A HOOK UP FOR UNITS WITH ORIGINAL THERMOSTATS CATALOG NUMBERS FOR ORIGINAL THERMOSTATS USED BEFORE 1 51 2000 ARE 701 51H4301 AND 2177101 o lt a a RED 208V ORANGE 240V HEAT PUMP LENN Xe OUTDOOR UNITS NOTE FOR USE WITH COPPER CONDUCTORS ONLY REFER TO UNIT RATING PLATE FOR MINIMUM CIRCUIT AMPACITY AND MAXIMUM OVER CURRENT PROTECTION SIZE WARNING ELECTRIC SHOCK HAZARD CAN CAUSE INJURY OR DEATH UNIT MUST BE GROUNDED IN ACCORDANCE WITH NATIONAL AND LOCAL CODES HP21 36 48 60 233 01 02 Supersedes Form No New Form No 533 357W 2000 Lennox Industries In
36. AUX HEAT 2 ELECTRIC SHOCK HAZARD CAN CAUSE INJURY OR DEATH UNIT MUST BE GROUNDED IN ACCORDANCE WITH NATIONAL AND LOCAL CODES COOL HEAT 2 REV VALVE DENOTES OPTIONAL COMPONENTS COOL HEAT S54 HOOKUP WITH WHITE RODGERS OR HEATCRAFT ELECTRONIC THERMOSTAT 2 N S54 amp HOOKUP WITH K4 GE OR HONEYWELL THERMOSTAT GH FUELMASTER HOOKUP WF DESCRIPTION KEY COMPONENT Al4 CONTROL TWO SPEED Bl COMPRESSOR B4 MOTOR OUTDOOR FAN CAPACITOR COMP HARD START Cle CAPACITOR DUAL CMCI CONTROL DEFROST COMPRESSOR HRI HEATER COMPRESSOR 1 J44 JACK TWO SPEED CONTROL Kl 1 2 CONTACTOR COMPRESSOR x K4 1 2 SIRELAY DEFROST RELAY HARD START BLACK COM RED 208V ORANGE 230V 24V COMMON K58 l RELAY LOW AMBIENT K69 1 2 CONTACTOR COMPRESSOR TWO SPEED N FOR USE WITH COPPER LI VALVE REVERSING CONDUCTORS ONLY P44 PLUG TWO SPEED CONTROL REFER TO UNIT RATING 2 RESISTOR BLEED PLATE FOR MINIMUM ARTS SENSOR AMBIENT COMPENSATION CIRCUIT AMPACITY 54 SWITCH LIMIT HI PRESS COMP 1 AND MAXIMUM FUSE SIZE SII SWITCH LOW PRESS LOW AMB A 540 THERMOSTAT CRANKCASE COMPRESSOR MOTOR A S54 THERMOSTAT SERVICE LIGHT THERMALLY PROTECTED TI9 TRANSFORMER COOLING CONTROL TBI5 TERMINAL STRIP LOW VOLTAGE LINE VOLTAGE FIELD INSTALLED CLASS II VOLTAGE FIELD
37. CK VOLTAGE ACROSS TERMINALS Y1 AND X AND Y2 AND X AT UNIT LOW VOLTAGE TERMINAL STRIP 15 IS VOLTAGE 24 6VAC NO _ YES CHECK INDOOR THERMOSTAT FOR MALFUNCTIONS REPLACE IF NECESSARY REPEAT TROUBLESHOOTING PROCEDURE IS CONTACTOR S COIL ENERGIZED YES EN S NO ARE CONTACTS CLOSING NO YES REPLACE CONTACTOR REPEAT TROUBLESHOOTING PROCEDURE CHECK STARTING CIRCUIT AND COMPRESSOR REPAIR OR REPLACE AS NECESSARY REPEAT TROUBLESHOOTING PROCEDURE TURN OFF POWER TO INDOOR AND OUT DOOR UNITS DISCONNECT TWO RED WIRES FROM TERMINALS 1 AND S2 OF TSC CHECK THE COMPRESSOR INTERNAL SENSORS BY CHECKING THE RE SISTANCE OHMS THROUGH THE RED WIRES CAUTION THE RED WIRES S1 AND S2 MUST BE DISCONNECTED FROM THE TSC FOR THIS TEST OR DAMAGE TO THE TSC COULD RESULT IS RESISTANCE WITHIN RE SET RANGE LISTED ON UNIT RATING PLATE YES i NO pm 1 RECONNECT RED WIRES TO S1 AND S2 AND RECONNECT JP44 RED WIRES ARE NOT POLARITY SENSITIVE ALLOW COMPRESSO SUFFICIENT TIME TO COOL TO RESET PERATURE CHECK INTERNAL WINDINGS OF COMPRESSOR WITH OHMMETER ARE WINDINGS OPEN OR SHORTED r L ves ___ REPLACE REPLACE TSC COMPRESSOR REPEAT TROUBLESHOOTING PROCEDURE CHECK VOLTAGE AT CONTACTOR COILS FOR SINGLE PHASE UNITS K1 AND K69 SHOULD BE ENERGIZED FOR THREE PHASE UNITS K1 ONLY SHOULD BE ENERGIZED IS VOLTAGE 24 6VAC YES NO TABLE 20b CONTINUED FROM
38. COMPONENTS ELE n SHOCK HAZARD CAN CAUSE INJURY H UNIT BE ACCORDANCE WITH NATIONAL AND LOCAL CODES New Form Ne 533 750W 200 Lennox Indvetrice Inc Lithe U S A Page 48 21 36 230 60 230 3 UNITS OPERATION SEQUENCE THREE PHASE COOLING SEQUENCE The TSC two speed control has an external temperature probe to lockout low speed during low temperatures plus a poten tiometer used for setting the low speed lock out temperature The adjustment range is 38 to 55 This lockout will occur in heating and cooling mode 1 1st stage cooling demand energizes TB15 Y1 and TB15 O 15 sends signal to O on defrost board which energizes reversing valve 11 TB15 Y1 energizes TSC terminal JP44 6 NOTE 2nd stage cooling demand may be energized direct ly without passing through 1st stage 2 TSC delays 3 seconds before responding to the new com mand 3 If the unit is changing from 2nd stage to 1st stage demand TSC initiates speed change delay and de energizes JP44 8 and JP44 9 to stop all unit operation for 60 5 seconds After TSC completes the 60 5 second speed change delay or if the unit is starting up in 1st stage directly from OFF mode TSC checks safety circuits by looking for 24VAC at JP44 7 and by checking resistance through wires connected to S1 and 52 4 If all safety circuits check out TSC energizes K1 and com pressor begins low speed startup 5 2nd stage cooling demand energizes TB15 Y1 TB15 Y2 and TB15
39. COMPRESSOR 1 JACK TWO SPEED CONTROL NTACTOR COMPRESSOR 1 DEFROST RED 208V ORANGE 230V 24 COMMON LINE VOLTAGE FIELD INSTA 77 CLASS II VOLTAGE FIE OR OUTDOOR FAN LOW AMBIENT OR COMPRESSOR TWO SPEED REVERSING WO SPEED CONTROL SENSOR AMBIENT COMPENSATION SWITCH LIMIT HI PRESS COMP SWITCH LOW PRESS LOW AMB THERMOSTAT CRANKCASE THERMOSTAT SERVICE LIGHT TRANSFORMER COOLING CONTROL TERMINAL STRIP LOW VOLTAGE LENNOX 2 inc WIRING DIAGRAM 7 94 EAT PUMP OUTDOOR UNITS DIN gt ON Pol TAB WUD Pl B EAT Ico kn TERM BOX HP21 415 515 655 4 5 Y 208 230 60 3 EAT PUMP SECTION 2B47 Supersedes Form No New Form No 551 183W 1994 Lennox Industries Inc Litho U S A 5 ROOM THERMOSTAT HP21 36 230 60 230 Wiring HARD START RELAY K69 2 CONTACTOR CONTACTOR CONTROL i 6 oyo QQ ci2 START DUAL K4 CAPACITOR CAPACITOR DEFROST RELAY EX E DOW TI9 TRANSFORMER OUTDOOR FAN MOTOR 540 54 LI BI TO 24 AESA CRANKCASE HIGH REVERSING COMPRESSOR POWER SOURCE
40. Close on Temperature Drop m Cut Out Open on Temperature Rise 55 2 F 47 2 F 50 2 F 65 2 F 55 has field adjustable setpoints Temperature differential difference between cut in and cut out is fixed and cannot be adjusted Table 9 shows S55 control setpoints The con trol is factory set to close at 40 2 F on a temperature drop and reset at 50 2 F on a temperature rise ADJUSTING SPEED CONTROL THERMOSTAT Adjustment screw can be Z Ves accessed by inserting screw driver through slot in underside of control box Turn screw clockwise to increase switchover temperature T FIGURE 11 Regional climatic conditions may require the control to be ad justed to a different setting The adjustment screw is located on the bottom of the control A hole cut into the bottom shelf of the control box provides access to the speed control from the compressor compartment see figure 11 Figure 12 shows the adjustment range of the control Turn adjustment screw clockwise to raise the switchover temperature and counter clockwise to lower the switchover temperature SPEED CONTROL THERMOSTAT ADJUSTMENT SCREW HP21 FACTORY SETTINGS FIGURE 12 R Reversing Valve and Solenoid L1 A refrigerant reversing valve with electromechanical sole noid is used to reverse refrigerant flow during unit operation The reversing valve is energized during cooling demand and during defrost S Ambient Compen
41. DS FOR CONTROL TO POWER UP APPLY THERMOSTAT DEMAND CHECK UNIT VOLTAGE AND MANUALLY RESET CONTROLS CONTROL WAS LOCKED OUT DUE TO UNIT PROB LEMS CONTINUE THROUGH TROUBLESHOOT ING FLOWCHART IN THE UNIT INFORMATION MANUAL TO LOCATE REASON FOR LOCKOUT SAFETY DORMANT LOCKOUT YES NO TRY TO START COMPRESSOR BY PRESSING AND RELEASING MANUAL OVERRIDE BUTTON DOES COMPRESSOR START CONTROL IS PROBABLY GOOD AND THE PROBLEM IS LOCATED ELSEWHERE IN THE UNIT PRO CEED THROUGH TROUBLE SHOOTING FLOWCHART IN THE UNIT INFORMATION MANUAL TO LOCATE THE PROBLEM START BY CHECKING ALL MANUALLY RESET CONTROLS Page 50 CONTROL IS NOW OUT OF SAFE TY DORMANT LOCKOUT AND HAS RESUMED NORMAL OPERATION DO NOT REPLACE CONTROL SAFETY DORMANT LOCKOUT WAS PROBABLY CAUSED BY A SELF TEST FAILURE OR LINE VOLTAGE SPIKE TABLE 20a HP21 UNIT CONTROLS DIAGNOSTICS START HERE I CHECK SUPPLY VOLTAGE IS SUPPLY VOLTAGE WITHIN RANGE SHOWN ON UNIT RATING PLATE NO Mn YES CORRECT POWER SUPPLY MANUALLY RESET HIGH PRESSURE SWITCH 54 IN OUTDOOR UNIT IF TRIPPED HIGH ales COOLING CHOOSE COOLING OR HEATING MODE 1 TURN INDOOR THERMOSTAT TO OFF POSITION SET INDOOR THERMOSTAT TO LOWEST TEMPERATURE SETTING TURN INDOOR THERMOSTAT TO COOL MODE IF POWER TO OUTDOOR UNIT HAS BEEN OFF WAIT AT LEAST 10 SECONDS TO ALLOW TSC TO POWER UP PUSH AND RELEASE THE OVERRIDE BUTTON ON THE TSC TO BY PASS THE 5 MINUTE TIMED OFF DELAY
42. ER COMPRESSOR JACK TWO SPEED CONTROL CONTACTOR COMPRESSOR RELAY DEFROST 24V COMMON BLACK COM RED 208V ORANGE 230V PLACE TEMPERATURE CONTROL DIAGRAM HERE lt D lt e 2 amp n mall lt LINE VOLTAGE FIELD INSTALLED CLASS II VOLTAGE FIELD WIRING SW LO EY CY T CONTACTOR COMPRESSOR TWO SPEED VALVE REVERS ING PLUG TWO SPEED CONTROL SENSOR AMBIENT COMPENSATION SWITCH LIMIT HI PRESS COMP 1 SWITCH LOW PRESS LOW AMB THERMOSTAT CRANKCASE THERMOSTAT SERVICE LIGHT TRANSFORMER COOLING CONTROL 1815 TERMINAL STRIP LOW VOLTAGE LENNOX res nc WIRING DIAGRAM HEAT PUMP OUTDOOR UNITS 21 415 2 5 HP21 513 2 3 Y 21 655 2 5 208 250 60 5 PUMP SECTION 2B47 Supersedes Form No New Form No 529 221W 1992 Lennox Industries Inc Litho U S A TERM BOX 21 4 5 Wiring Single Phase Units Shown R 24V POWER s HB FOR 621 DS FOR 621 CB CBH21 BLOWER AUX HEAT
43. ESSO VALVE il EXPANSION VALVE NOTE Bold arrows indicate direction of refrigerant flow in cooling mode FIGURE 16 Page 20 E Filter Drier All HP21 units are equipped with a filter drier located in a circuit parallel to the expansion valve The filter drier is equipped with an internal check valve In heating mode when refrigerant flow is reversed the check valve is forced closed and refrigerant is routed through the expansion valve During cooling mode the check valve opens and re frigerant flows freely through the filter drier HP21 6 and late model HP21 units will use a Biflow filter drier F Expansion Valve All HP21 series units use an externally equalized thermal expansion valve as the primary expansion device in the outdoor unit The expansion valve is factory set non ad justable and non serviceable HP21 6 and late model HP 21 units will use an expansion valve with internal check valve to pair with the biflow filter drier G Discharge Muffler All units are equipped with a discharge muffler connected between the compressor discharge port and the reversing valve The discharge muffler is located immediately in front of the compressor in the compressor compartment See figure 19 H Accumulator All units are equipped with a suction line accumulator con nected between the reversing valve and the compressor suction port The accumulator is located immediately be hind th
44. FIGURE 24 Page 27 FIELD WIRING DIAGRAM 21 WITH CB31MV CLASS 2 VOLTAGE FIELD INSTALLED NEC CEC NOTE ALL REMAINING WIRES FACTORY INSTALLED S THERMOSTAT 8 6 5 O D 25 01 MIREI ece TERMINAL BLOCK AN N NEC CEC CLASS 2 3VA COMPRESSOR YELLOW COMPRESSOR BLACK COMMON WHITE ELECTRIC HEAT ORANGE REVERSING VALVE SERVICE LIGHT THER A FACTORY SUPPLIED FIELD INSTALLED JUMPERS REQUIRED Humidity Outdoor Unit Required With CCB1 Single Speed Heat Pump Y1 to Y2 Humidity Control Two Speed Heat Pump Without CCB1 single Speed Heat Pump DS to Y1 and Humidity Y1 to Y2 HEAT PUMP CLASS 2 Control Two Speed Heat Pump DS to Y1 VOLTAGE TERM I NALS BLUE PURPLE THERMISTOR 3 FACTORY INSTALLED JUMPER FIGURE 25 Page 28 Sequence Compressor Single Phase Compressor Startup Figure 26 shows single phase compressor windings This compressor has a two speed capacitor start capacitor run motor For starting the start and run capacitors are in par allel to provide the proper starting torque The start capacitor is disconnected by the start relay when the com pressor comes up to speed The run capacitor remains connected to the start winding and the motor runs as a two phase induction motor with improved power factor and torque characteristics provided by the capacitor Low speed compressor operation is provided by powering the
45. High K1 amp K69 K69 Compressor Speed In single phase units K1 also de energizes the crankcase heater during compressor operation Contactor K69 Contactor K69 energizes high speed operation in all units single phase and three phase In single phase units K69 is a five pole contactor with three sets of normally open contacts and two sets of normally closed contacts In three phase units K69 is a three pole contactor with three sets of normally open contacts This contact arrangement pro vides unique switching characteristics for two speed operation K69 is also equipped with a set of single pole double throw auxiliary contacts located on the side of the contactor The contactor is energized in response to high speed thermostat demand from JP44 8 two speed control jackplug J44 P44 pin 8 Contactor Operation Single Phase Units Low speed demand energizes K1 K1 de energizes the crankcase heater and energizes the compressor High speed demand energizes both contactors K1 and K69 K69 N O contacts close to redirect the circuit to the high speed start windings and the N C contacts open to de energize the low speed start windings K69 N C contacts also switch whenever K69 is energized to ensure that K1 is energized with K69 during high speed operation refer to unit wiring diagram Contactor Operation Three Phase Units Low speed demand energizes K1 K1 energizes the com pressor and locks out contactor K
46. INDING HEAT PUMP SECTION 2B46 TERM BOX Supersedes Form No New Form No 114 528 890W 529 120W Litho U S A G SINGLE PHASE DEFROST SEQUENCE 3 Refer to the unit component section of this manual for detailed defrost control operation Defrost is terminated when relay K4 is de ener 1 When the defrost control determines a defrost needs to be initiated it closes an internal relay connected to DEF RLY terminal Relay 4 is energized Relay K4 controls defrost gized Thermostat Demand Satisfied 4 When thermostat demand is satisfied or if thermostat is switched OFF or switched to heating mode all outdoor unit operation stops after a valve K4 2 opens to de energize the outdoor fan and K4 3 closes to delay of 3 seconds TSC then completely resets erase accumulated energize auxiliary heat faults before cycling through the 5 minute timed off delay 2 When relay K4 energizes K4 1 switches to energize the reversing Page 34 24V amp e BLOWER AUX HEAT AUX HEAT 2 66 COOL 2 REV VALVE COOL HEAT BLACK COM DESCRIPTION COMPONENT 1 control two speed HC compressor motor outdoor fan capacitor outdoor fan control defrost comp COM heater comp T E jack two speed control EQUIP VY contactor comp GROUND relay defrost COMMON 2605 666 RED 208V ORANGE 230V
47. LE PHASE LINE VOLTAGE FIELD WIRING 208 230 60 1 L2 L1 0 10 COMPRESSOR CONTACTOR REFER TO UNIT RATING PLATE FOR MAXIMUM CIRCUIT AMPAC ITY AND MAXIMUM FUSE SIZE A uf lt lt gt lt 2 gt 1 Wi TERMINAL BLOCK 5 05 G 4 AMP ELECTRIC T A TWO STAGE THERMOSTAT IS USED CT SECOND S EAT BULB TO AL W2 R BETWEEN ALS R AN OUTDOOR THERMOSTA SED CT LEADS TO TERMI AND WS REMOVE JUMPER RGENCY HEAT RELAY USED ONLY IF TDOOR THERMOSTAT IS USED FIELD PROVIDED AND INSTALLED NEAR INDOOR UNIT 24VAC 5VA MAX NEC CLASS 2 EC CEC CLASS 2 3VA HEAT PUMP LOW VOLTAGE JUNCTION BOX YELLOW COMMON PINK COMPRESSOR RED PINK COMPRESSOR LIGHT PURPLE THERMISTOR ORANGE ELECTRIC HEAT BLACK REVERSING VALVE SERVIC FIELD INSTALLED JUMPERS REQUIRED FOR TERMINAL STRIP TB1 Humidity Outdoor Unit Jumpers Control Required With CCB1 Single Speed Heat Pump Y1 to Y2 Humidity Control Two Speed Heat Pump Without CCB1 Single Speed Heat Pump DS to Y1 Humidity Control Two Speed Heat Pump DS to Y2
48. METER DEFROST CONTROL__ gt f d AMBIENT SENSOR J INDOOR UNIT Sa CHECK gt CRANKCASE THERMOSTAT XQ A E m COMPRESSOR VALVE NOTE Bold arrows indicate direction of refrigerant flow in cooling mode EXPANSION VALVE FIGURE 18 Page 21 21 PLUMBING COMPONENTS CONTROL BOX HP21 1 shown Cue EXPANSION VALVE DISTRIBUTOR FILTER DRIER WITH INTERNAL CHECK VALVE EXPANSION VALVE EQUALIZER LINE CHARGE COMPENSATOR VAPOR 0 MANIFOLD 7 4 REVERSING VALVE DISCHARGE MUFFLER FIGURE 19 J Charge Compensator HP21 410 650 36 and 60 series units are equipped with a charge compensator located in the vapor line
49. NENTS Geni Litho U S A Page 46 21 36 230 60 230 3 UNITS OPERATION SEQUENCE SINGLE PHASE COOLING SEQUENCE The TSC two speed control has an external temperature probe to lockout low speed during low temperatures plus a poten tiometer used for setting the low speed lock out temperature The adjustment range is 38 to 55 This lockout will occur in heating and cooling mode 1 1st stage cooling demand energizes TB15 Y1 and TB15 O 15 sends signal to O on defrost board which energizes reversing valve 11 TB15 Y1 energizes TSC terminal JP44 6 NOTE 2nd stage cooling demand may be energized direct ly without passing through 1st stage 2 TSC delays 3 seconds before responding to the new com mand 3 If the unit is changing from 2nd stage to 1st stage demand TSC initiates speed change delay and de energizes JP44 8 and JP44 9 to stop all unit operation for 60 5 seconds After TSC completes the 60 5 second speed change delay or if the unit is starting up in 1st stage directly from OFF mode TSC checks safety circuits by looking for 24VAC at JP44 7 and by checking resistance through wires connected to S1 and S2 4 If all safety circuits check out TSC energizes K1 and com pressor begins low speed startup 5 2nd stage cooling demand energizes 15 1 TB15 Y2 15 TB15 Y2 energizes TSC terminal JP44 4 TB15 Y1 energizes TSC terminal JP44 6 6 TSC delays 3 seconds before respond
50. OL HEAT 660 5 i lt d DESCRIPTION gt control two speed o compressor e ne motor outdoor fan 1 C ui capacitor outdoor fan 5 capacitor compressor Z capacitor comp hard start control defrost comp Q heater comp L EQUIP jack two speed control 7 GROUND contactor comp COMMON relay defrost L relay hard start K69 1 2 contactor comp 2 speed LI valve reversing P44 plug two speed control 21 resistor bleed RTS sensor ambient comp 51 thermostat room 54 switch limit hi press comp S40 thermostat crankcase A FOR USE WITH COPPER K31 554 thermostat service light CONDUCTORS ONLY S55 thermostat s d trol peed contro REFER TO UNIT RATING 19 transformer cooling contro PLATE FOR MINIMU CIRCUIT AMPACITY 5 terminal strip low voltage AND MAXIMUM FUSE 8 COMPRESSOR MOTOR LENNOX wricsivies nc WIRING DIAGRAM THERMALLY PROTECTED ica wes UN HEAT PUMP OUTDOOR UNITS DESIGNATIONS 21 411 ere 21 511 21 651 LD INSTALLED Eo SPEED 208 250 60 1 VOLTAGE W
51. ORANGE COMMON THERMOSTAT PRESSURE VALVE 20 VA MINIMUM PURPLE CAPACITOR D i L NEC CLASS 2 BLACK RUN 42 L m GROUND LUG e D 208 230 60 TO BLOWER RELAY IN INDOOR UNIT TO EMERGENCY HEAT RELAY OUTDOOR FAN MOTOR LEADLESS pes ORANGE COMMON S54 B SERVICE THERMOSTAT AFTER 31 2000 SERVICE LIGHT CONTROL S54 WILL BE WIRED BETWEEN L AND WI ON TBIS ON ALL UNITS BUILT BEFORE 1 31 2000 SERVICE LIGHT CONTROL IS EITHER WIRED BETWEEN L AND YI ON TBIS OR L TBIS AND C COMMON 24V POWER WIRE A HOOK UP FOR UNITS WITH ORIGINAL THERMOSTATS CATALOG NUMBERS FOR ORIGINAL THERMOSTATS USED BEFORE 1 51 2000 ARE 51 5701 51H4301 AND 21J7101 vy B4 LEADLESS ey FAN MOTOR BIO BLACK COM RED 208V ORANGE 240V HEAT PUMP LENNOX UNITS NOTE FOR USE WITH COPPER CONDUCTORS ONLY REFER TO UNIT RATING 21 56 48 60 250 01 02 PLATE FOR MINIMUM CIRCUIT AMPACITY AND MAXIMUM OVER CURRENT PROTECTION SIZE Supersedes Form No WARNING ELECTRIC SHOCK HAZARD CAN CAUSE INJURY OR DEATH UNIT MUST BE GROUNDED IN ACCORDANCE New Form No WITH NATIONAL AND LOCAL CODES 533 356W M LINE VOLTAGE FIELD INSTALLED CLASS 11 VOLTAGE FIELD INSTALLED 2000 Lennox Industries Inc Litho U S A Q OUTDOOR FAN AY REL CONTACTOR 8666 4 DEFROST RELAY 5959 OLORO CAPACITOR LI 540 CRANKCASE Dever ves VALVE THERMOST
52. PRESSURE SWITCH S4 CRANKCASE THERMOSTAT 540 COMPRESSOR B1 AMBIENT AIR PORT DEFROST CONTROL AMBIENT SENSOR FIGURE 1 I APPLICATION All major components indoor blower coils must be matched according to Lennox recommendations for the compressor to be covered under warranty Refer to Engi neering Handbook for approved system matchups A misapplied system will cause erratic operation and can re sult in early failure of compressor or other components II UNIT COMPONENTS A Control Transformer T19 All units are equipped with a line voltage to 24VAC trans former which supplies power to unit controls as shown in table 1 Refer to unit wiring diagram for detailed information regarding unit wiring B Contactors K1 and K69 The compressor is energized by a set of contactors located in the control box Contactors in HP21 units are energized as shown in table 2 Page 3 TABLE 1 ezrcomponem source iPower no Speed Control ata comas O onar Cd High Pressure misa crancase Thermostat S40 Defrost Speed Control Thermostat 555 Service Light Thermostat s54 ambient Thermistor RT Potente Reys Bleed Resistor R21 24VAC from Outdoor Unit Transformer T19 24VAC from Indoor Unit Transformer T1 Line Voltage Fan Capacitor C1 Compressor B1
53. RATURE SETTING 4 TURN INDOOR THERMOSTAT TO HEAT MODE 5 IF POWER TO OUTDOOR UNIT HAS BEEN OFF WAIT AT LEAST 10 SECONDS TO ALLOW TSC TO POWER UP 6 PUSH AND RELEASE THE OVERRIDE BUTTON ON THE TSC TO BY PASS THE 5 MINUTE TIMED OFF DELAY 7 ALLOW 1 MINUTE FOR THE UNIT TO START DOES UNIT START AND RUN ON HIGH SPEED IN HEATING MODE GO TO NO l YES 1 HIGH SPEED HEATING LOW SPEED HEATING TURN INDOOR THERMOSTAT TO OFF POSITION REMOVE THE JUMPER WIRE FROM ACROSS SPEED CON TROL THERMOSTAT 555 OUTDOOR UNIT DISCONNECT THE FACTORY WIRING FROM EITHER SIDE OF SPEED CONTROL THERMOSTAT S55 SET INDOOR THERMOSTAT TO HIGHEST TEMPERATURE SETTING TURN INDOOR THERMOSTAT TO HEAT MODE IF POWER TO OUTDOOR UNIT HAS BEEN OFF WAIT AT LEAST 10 SECONDS TO ALLOW TSC TO POWER UP PUSH AND RELEASE THE OVERRIDE BUTTON ON THE TSC TO BYPASS THE 5 MINUTE TIMED OFF DELAY ALLOW 1 MINUTE FOR THE UNIT TO START DOES UNIT START AND RUN ON LOW SPEED IN HEATING MODE lt NO _ YES GO TO B ON NEXT PAGE LOW SPEED HEATING O K TSC OPERATING PROPERLY REASSEMBLE UNIT CHECK VOLTAGE ACROSS TERMINALS O AND X AT UNIT LOW VOLTAGE TERMINAL STRIP TB15 IS VOLTAGE 24 6VAC YES ES E NO CHECK REVERSING VALVE CHECK INDOOR THERMO FOR MALFUNCTIONS STAT FOR MALFUNCTIONS REPLACE IF NECESSARY REPLACE IF NECESSARY REPEAT TROUBLESHOOTING PROCEDURE CONTINUED FROM ON PREVIOUS PAGE CHE
54. ROCEDURE TROUBLESHOOTING PROCEDURE 1 TROUBLESHOOT ING PROCEDURE CHECK VOLTAGE ACROSS PINS 1 AND 2 OF JP44 IS VOLTAGE 24 6VAC YES NO RECONNECT RED WIRES TO S1 CHECK WIRING AND S2 AND RECONNECT JP44 CONNECTIONS RED WIRES ARE NOT POLARITY SENSITIVE REPEAT TROUBLE REPEAT SHOOTING PROCEDURE TROUBLESHOOTING PROCEDURE Page 52 SERVICE NOTES Page 53
55. WIRIING LENNOX stios ne WIRING DIAGRAM 2 2 HI SPEED START HEAT PUMP OUTDOOR UNITS 21 411 2 3 KO SREED HP21 511 2 3 P 21 651 2 5 TART 2 208 230 60 I TERM BOX HEAT PUMP SECTION 2B46 Supersedes Form No New Form No 529 222W 1992 Lennox Industries Inc Litho U S A Lp 21 2 3 Wiring Three Phase Units Shown 24V POWER TBIS Al4 E M r HB FOR G21V HB FOR G2iVB CB DS CBH21V 05 ECON BLOWER AUX HEAT 1 AUX HEAT 2 NOTE ELECTRIC SHOCK HAZARD CAN CAUSE INJURY OR DEATH UNIT MUST BE GROUNDED IN ACCORDANCE WITH NATIONAL AND LOCAL CODES COOL HEAT 2 REV VALVE DENOTES OPTIONAL COMPONENTS COOL HEAT FOR USE WITH COOPER CONDUCTORS ONLY REFER TO UNIT RATING PLATE FOR MINIMUM CIRCUIT AMPACITY AND MAXIMUM FUSE SIZE A COMPRESSOR MOTOR THERMALLY PROTECTTED A 534 HOOKUP WITH WHITE RODGERS OR HEATCRAFT ELECTRONIC THERMOSTAT A 354 OR RT3 HOOKUP WITH GE OR HONEYWELL THERMOSTAT ij DESCRIPTION KEY COMPONEN 14 CONTROL TWO SPEED BI COMPRESSOR B4 MOTOR OUTDOOR FAN A C CAPACITOR OUTDOOR FAN RT3 1 CONTROL DEFROST COMPRESSOR 1 HEAT
56. at low or high speed as determined by the outdoor ambient W1 energizes the indoor auxiliary heat relay for 2nd stage heat DEFROST SEQUENCE Upon initial power up or first heating demand after cooling mode a sacrificial defrost operation will occur in order to cali brate the board Calibration will occur after accumulated com pressor run time of 34 minutes and coil temperature is below 35 13 Y1 is energized in HEAT mode de energizing reversing valve 14 Compressor run time of 34 minutes accumulated Defrost begins N C outdoor fan relay K10 remains open allowing fan to cycle during defrost 15 Defrost will last a maximum of 14 minutes or until the coil temperature sensed at the coil probe exceeds the selected pin termination temperature Pin values are 50 60 70 and 80 Factory setting is 70 Vill TROUBLESHOOTING FLOWCHARTS The following flowcharts show how to diagnose problems in two speed heat pumps equipped with TSC control Table 19 shows how to determine if the TSC is functioning Tables 20a and 20b show how to correlate TSC diagnostics to the unit Follow the flowcharts step by step Disconnect as few wires as possible Any time a repair is made reassemble the unit and retest for operation If the unit does not oper ate recheck up to that point and then continue through the chart Occasionally more than one specific problem may exist Do as little disassembly as possible and double check your d
57. between the reversing valve and outdoor coil manifold Figure 19 shows the relative location of the charge compensator in the unit The compensator is used to collect and store ex cess refrigerant in the heating mode Figure 20 shows operation of the charge compensator The charging procedure for these units is unchanged Fol low the charging procedure outlined in the installation instructions or in the Unit Information Manual In heating mode the vapor line passing through the charge compensator tank is cooler than the liquid line Excess re frigerant condensed liquid from the indoor coil is trapped by the compensator The vapor is cooler than the liquid line so liquid migrates from the liquid line to the compensator tank where it is stored In cooling mode the vapor line passing through the charge compensator tank is hotter than the liquid line Stored liquid is boiled and forced back into the liquid line for circulation EXPANSION VALVE SENSOR CAP TUBE STRAINER CHARGE COMPENSATOR LIQUID LINE VAPOR LINE SERVICE VALVE EXPANSION VALVE SENSING BULB THERMOMETER WELL 411 511 651 ONLY LIQUID LINE SERVICE VALVE ACCUMULATOR BEHIND COMPRESSOR HP21 6 AND LATE MODEL UNITS WILL HAVE A BIFLOW FILTER DRIER AND EXPAN SION VALVE WITH INTER NAL CHECK VALVE CHARGE COMPENSATOR OPERATION COOLING MODE Vapor Line To Outdoor Coil Compensator Tank P cooling mode the
58. button when pressed and released bypasses the five minute delay so low speed or high speed operation can be im mediately energized However the control provides a one minute delay between speed changes which can not be bypassed Do not use the override button immediately after power up If the button is pushed during the ten second power up delay it has no effect The control completes the five minute delay The control continually self tests its internal circuits and uses the diagnostic lights to indicate control failure Page 11 TSC 6 SHOWN Normal Operation Sequence After self test the control begins a five minute delay dur ing which the unit is not operational control and outdoor unit do not respond to thermostat demand Once the five minute delay is complete the control waits in OFF mode for thermostat demand After receiving a thermostat demand the TSC de lays three seconds before responding Low speed demand JP44 9 energizes low speed operation OR high speed demand JP44 8 ener gizes high speed operation During unit operation if low speed demand changes to high speed demand or if high speed demand changes to low speed the control delays three sec onds before responding Then all unit operation stops for 60 5 seconds control de energizes JP44 8 and JP44 9 This allows refrigerant pres sure to equalize in the system At the end of the 60 5 second delay the control responds to whatever thermos
59. c Litho U S A 21 36 230 60 230 3 UNITS SINGLE PHASE EA ART 69 2 CONTACTOR CONTACTOR EEG ag ss 7 T i START CAPACITOR CAPACI ITOR GROUND LUG s 208 230 60 1 OUTDOOR MOTOR S40 S4 LI BI CRANKCASE ae ONE COMPRESSOR i 7 ORANGE COMMON THERMOSTAT VALV 20 VA DUAE CL a NEC CLASS 2 OUTDOOR FAN MOTOR 9 68 LE ORANGE COMMON sm TO EMERGENCY HEAT RELAY e TO BLOWER RELAY IN INDOOR UNIT S54 SERVICE ALTER 1 31 2000 SERVICE LIGHT CONTROL THERMOSTAT 554 WiLL WIRED BETWEEN L a UNITS BUILT BEFORE 1 31 2000 LIGHT CONTROL IS EITHER WIRED BETWEEN L AND ON IBS OR L TBIS AND C COMMON 24V POWER WIRE HOOK UP FOR UNITS WITH ORIGINAL THERMOSTATS CATALOG NUMBERS FOR ORIGINAL THERMOSTATS USED BEFORE 1 31 2000 ARE 51H3701 5IH4301 AND 2177101 s 0 2 pm p pt Ei a QO 6 O le COIL l B4 LEADLESS FAN MOTOR BLACK COM RED 208V ORANGE 240V SeNsoRS LS 62 FOR USE WITH COPPER CONDUCTORS HP21 36 48 60 230 03 ONLY REFER TO UNIT RATING 14 MINIMUM CIRCUIT AMPAC MAXIMUM OVER upersedes Form No CURRENT PROTECTION SIZE S EE OR EE HAZARD NJURY OR DEATH UNIT 555 556 0 BE SEn QUNDED IN ACCORDANCE New Form No WITH NATIONAL AND LOCAL CODES LINE VOLTAGE FIELD INSTALLED 533 749W CLASS VOLTAGE FIELD INSTALLED DENOTES OPTIONAL COMPO
60. capacitor is located in the unit control box and is electrically connected as shown in the unit wiring diagram Run capacitors are wired in parallel with the start capacitor See side of capacitor for ratings N Fan Capacitor C1 All early model HP21 1 2 3 single phase and all HP21 three phase series units regardless of dash number use single phase PSC outdoor fan motors which require an ex ternal run capacitor The fan capacitor is located inside the unit control box See side of fan capacitor for ratings O Dual Capacitor C12 HP21 4 5 and late model single phase units use a single dual capacitor to maximize motor efficiency in both the fan motor and the compressor which use PSC motors A dual capacitor has two independent capacitors inside one can Each side of the capacitor has different ratings See side of capacitor for ratings The dual capacitor is wired in parallel with the start capacitor and is electrically connected as shown in the unit wiring diagram P Two Speed Controls ELECTROSTATIC DISCHARGE ESD Precautions and Procedures CAUTION Electrostatic discharge affect electronic components Take precautions during unit installation and service to protect the unit s electronic controls Precautions will help to avoid control exposure to electrostatic dis charge by putting the unit the control and the technician at the same electrostatic potential Neutralize electrostatic charge by touching hand
61. ce It is likely that the control could count three unit faults from the crankcase temperature switch during a single thermostat demand since this switch resets automati cally However the cycle counter can only count unit faults from the high pressure switch if the reset button is pushed without interrupting thermostat demand 2 all units using the TSC two speed control terminals 51 and 52 on the control are connected to temperature sensors thermistors which monitor the temperature of the compressor motor windings The two speed control measures the resistance through the sensors The sensors increase their resistance as temperature increases for example too much superheat When the resistance through the sensors increases above a preset limit the control stops compressor operation As the compressor windings cool the resistance through the sensors drops below the reset limit the control resets automatically and one fault is counted NOTE Intermittent continuity bad connection or failing components can cause false lockout or lit LED Check all electrical connections thoroughly The sensors can be checked by measuring resistance ohms through the sensors with the wires discon nected from the control unit not running The sensor wires are not polarity sensitive Table 3 shows winding temperature sensor resistance values which will cause the TSC to lock out When the unit is operating normal ly the resistance through
62. cy of 5PSIG 1 Connect gauge manifold as shown in figure 16 Con nect an upright R 22 drum to center port of gauge manifold 2 Record outdoor ambient temperature 3 If indoor temperature is below 74 F set room thermo stat to 74 F 23 C in Emergency Heat or Heat position and allow unit to run until heating demand is satisfied This will create the necessary load for proper charging of system in cooling cycle Change thermo stat setting to 68 F 20 C in Cool position Allow unit to run until system pressures stabilize 4 Make sure thermometer well is filled with mineral oil before checking liquid line temperature NOTE When checking or adjusting charge compres sor should always be on high speed and indoor blower should be on cooling high speed For cooling mode set room thermostat at lowest setting For heating mode place a jumper across speed control thermostat S6 in outdoor unit and then reset the room thermostat to OFF and back to HEAT OUTDOOR TEMPERATURE ABOVE 60 F step 5 5 If ambient temperature is above 60 F system should be charged using the approach method Place ther mometer in well and read liquid line temperature The difference between liquid line temperature and ambi Page 24 ent temperature is the approach temperature Approach temperature should match the values shown in table 16 Add refrigerant to reduce approach temperature and remove refrigerant to increase ap proach
63. d change delay and automatically ener gizes low speed The setpoint can be changed by adjusting the poten tiometer shown in figure 6 The potentiometer is factory set as shown in table 5 TABLE 5 Speed Control Thermostat Adjustable Range Factory Setting Max Min Mid Cut In 42 F 46 2 F 42422 50 Close on Temperature Drop 42 2 F 55 2 F Cut Out 429F 56 2 420 Open Temperature Rise NE 52 2 F 65 29 To adjust the speed control thermostat insert a small slot screwdriver into the potentiometer as shown in fig ures 6 and 7 To lower the setpoint turn the potentiometer counter clockwise To raise the setpoint turn the potentiometer clockwise Do not force the po tentiometer to turn past its stops the potentiometer will be damaged TSC 3 TWO SPEED CONTROL WINDING TEMPERATURE SENSOR TERMINALS OVERRIDE BUTTON 5 minute delay SENSOR TEMPERATURE ADJUSTMENT shown in factory position FIGURE 7 The unit wiring diagrams have been revised to reflect the changes for the HP21 2 TSC 3 and are shown in section Vil Wiring Diagrams and Operation Sequence Page 10 TSC 6 Two Speed Control HP21 4 and 5 and late model HP21 units single and three phase are equipped with a TSC 6 two speed con trol The TSC 6 A14 two speed control contains relays which energ
64. d disconnect from gauge manifold center port Release nitrogen pressure from system Reconnect vacuum pump to gauge manifold center port Evacuate system through manifold service valves until vacuum in system does not rise above 29 7 inches 754mm mercury 5mm absolute pressure within a 20 minute period after stopping vacuum pump 6 After evacuation is complete close manifold center port and connect refrigerant drum Pressurize system slightly with refrigerant to break vacuum 1 1 1 C Charging The system should be charged in the cooling cycle if weath er conditions permit The following procedures are intended as a general guide and slight variations in temper ature and pressure should be expected Large variations may indicate a need for further servicing If the system is completely void of refrigerant the recom mended and most accurate method of charging is to weigh the refrigerant into the unit according to the total amount shown on the unit nameplate and in table 14 Refer to the Lennox Unit Information Service manual for proper proce dure If weighing facilities are not available or if unit is just low on charge the following procedures apply BEFORE CHARGING steps 1 through 4 NOTE The following procedures require accurate readings of ambient temperature liquid temperature and liquid pressure for proper charging Use a ther mometer with accuracy of 2 F and a pressure gauge with accura
65. d to the control The red probe is used to measure ambient air temperature and the blue probe is used to measure liquid line temperature The ambient probe is attached inside the ambient air port lo cated in the lower right corner of the compressor compartment see figure 1 The liquid line probe is at tached to the cooling liquid line adjacent to the expansion valve The temperature probes cannot be detached from the con trol The control and the attached probes MUST be replaced as a unit Do not attempt to cut or splice probe wires Operation On compressor startup the control begins measuring com pressor run time The control measures run time for the current thermostat demand cycle and total run time since the last defrost Two minutes after receiving a thermostat demand after two minutes of cycle run time the control begins to mea sure liquid line temperature When the liquid line temperature drops below 39 F the control begins to moni tor ambient temperature and to measure lockout time Lockout time is defined as the amount of time the heating mode can continue before initiating a defrost The amount of lockout time which can be accumulated is determined by Page 17 ambient temperature as shown in table 11 When the con trol reaches the amount of lockout time determined by the ambient temperature the control proceeds to the next step TABLE 11 Lockout Time Minutes HP21 411 511 HP21 651 HP21 413 51
66. e Across TSC 6 compressor sensor terminals with Unit Running DC Volts Short in Sensor DC volts Measured with unit running Resistor Compressor MODE SELECTION JUMPERS The control has six mode selection jumpers for selection of operating modes and problem code recall or test Choose one of the first four modes for operation Normal Normal operation default mode Unit runs on high or low speed as the indoor thermostat load demands Latch 1 After high speed demand is met the unit remains in high speed until the low speed demand is satisfied Latch 2 After the unit operates in low speed for 15 minutes consecutively it switches to high speed until low speed demand is satisfied Latch 3 After the unit operates in low speed for 30 minutes consecutively it switches to high speed until low speed demand is satisfied Recall Used in conjunction with the bypass button to recall the stored problem codes Test Used in conjunction with the control button to start test mode Latch 2 or 3 modes are recommended in high humidity areas If the jumper falls off or is removed the control will continue to operate in the previously set mode until the control is reset due to loss of power then the control will default to the Normal mode TEST MODE The control has a test mode To initiate this mode move the jumper to the test position and push the control button The unit will o
67. e Option 2 safety device switch opens Code 10 is stored Code 11 Compressor Temperature Sensor Shorted This code indicates that the compressor temperature sensor wires have shorted together Code 11 is stored Code 12 Outdoor Temperature Sensor This code indicates a problem with the operation of the out door temperature sensor Code 12 is stored Page 15 Code 13 Not Used This code may be used in future models of the two speed con trol but at this time has no function and therefore is not stored Code 14 Test Mode Code 14 does not indicate a problem The control is in TEST mode when this code is displayed See Mode Jumper Selec tions section Code 15 No Jumper in Place Code 15 is displayed when the mode jumper is not in place Make sure jumper is placed securely across the selected set of pins for the appropriate mode of operation SERVICE RELAY The control has a built in service relay This relay controls the thermostat service light or communicates with an alarm de vice The relay signals the alarm device in such a manner that the alarm device can distinguish between a lock out and a non lock out condition The relay contacts are normally open when no problems or lock out conditions occur A non lock out condi tion is reported by closing the contacts for the duration of the next no demand period If the control goes into a lock out state the relay will close and remain closed until the next loss of de
68. e check valve is open when the unit is in cooling mode and refriger ant is forced through the drier Separate discharge and suction service ports are provided at the compressor for connection of gauge manifold during charging procedure Figures 16 and 18 show HP21 gauge connections C Reversing Valve HP21 units are equipped with a reversing valve which is used to reverse refrigerant flow The valve is de energized during heating mode to direct discharge gas to the indoor coil The valve is energized during cooling mode and dur ing defrost to direct discharge gas to the outdoor coil A 24 volt solenoid is used to energize the reversing valve during cooling and defrost demand D Strainer All units are equipped with a liquid line strainer located ad jacent to the expansion valve The strainer is used to protect the expansion valve from particulate matter enter ing the system such as during charging CHARGE COMPENSATOR FILTER DRIER WITH INTERNAL CHECK VALVE LL PRESSURE 1 SWITCH MUFFLER ACCUMULATOR LIQUID LINE REVERSING VALVE i A BN L VAPOR LINE VALVE iE THERMOMETER C WELL x INDOOR UNIT CRANKCASE THERMOSTAT DEFROST CONTROL __ AMBIENT SENSOR CHECK COMPR
69. e compressor in the compressor compartment See figure 19 EXPANSION VALVE ae DEFROST CONTROL SENSOR OO E FiLTERDRIER 4 WITH INTERNAL 9 HEATING CYCLE CIRCUITRY OUTDOOR CHARGE The accumulator can be accessed without removing the compressor To access the accumulator remove the out door fan guard Then remove the fan motor and bracket as an assembly By reaching inside the fan opening remove all screws securing the compressor wrapper to the unit see figure 17 Then hinge the wrapper up out of the way to access the accumulator ACCESS TO ACCUMULATOR REMOVE FAN GUARD AND FAN REACH THROUGH OPENING REMOVE SCREWS SECURING WRAPPER TO UNIT HINGE WRAPPER OUT OF WAY FIGURE 17 Well Early model units only are equipped with a thermometer well for use in measuring liquid line temperature when charging the unit The thermometer well is used in all Len nox recommended charging procedures It is located in the liquid line adjacent to the liquid line service valve GAUGE MANIFOLD 99 COMPENSATOR CHECK VALVE e STRAINER HIGH PRESSURE SWITCH _ gt MUFFLER REVERSING VALVE V c3 ACCUMULATOR LIQUID LINE 4 4 Ex VAPOR LINE iu VALVE S id N THERMO
70. e problem Start by checking all manually reset controls high pressure switch etc Service Instructions 1 If light comes on and stays lit turn off power at dis connect for at least 3 seconds NOTE Breaking thermostat demand will not reset the control if the control is in a Safety Dormant Lockout 2 If LED is on when power is restored replace TSC 3 If light goes out see troubleshooting flowchart in Unit Information Manual TSC 3 Two Speed Control All early model 21 2 series units single and three phase are equipped with a TSC 3 two speed control The speed control thermostat formerly key number S55 has been removed from the unit and incorporated into the cir cuitry of the TSC 3 control see figure 6 The function and operating sequence are otherwise identical to the TSC 2 plus the separate thermostat used in previous 21 units The purpose of the speed control thermostat is to force the compressor to operate on high speed when outdoor tem perature is low It initiates a speed change delay and automatically energizes high speed when temperature drops below the setpoint The setpoint is factory preset and can be field adjusted TSC 3 TWO SPEED CONTROL with built in speed control thermostat TWO SPEED CONTROL TEMPERATURE ADJUSTMENT potentiometer 22 po lt gt SENSOR SCREWDRIVER FIGURE 6 When temperature rises above the setpoint the control initiates a spee
71. e the outdoor fan and de energize the crank case heater Outdoor fan begins operating immediately 2 After appropriate time delay and if all safety circuits check out TSC energizes JP44 9 Contactor K1 is energized through K69 2 N C con tacts 3 1 contacts close to begin compressor low speed startup K1 N C contacts open to disconnect the high speed wiring circuitry 4 Compressor B1 terminal 1 is energized by K1 contacts L1 T1 Com pressor terminal 2 is energized by contactor K1 terminal L2 T2 Compressor terminal 3 is energized by contactor K1 terminal L3 T3 This arrangement forms a series DELTA connection to the motor wind ings for low speed HIGH SPEED 5 High speed demand energizes JP44 4 6 After appropriate time delay and if all safety circuits check out TSC en ergizes JP44 8 7 When contactor K1 is de energized contacts K1 1 normally closed contacts form a parallel DELTA connection to the motor windings for high speed 8 Contactor K69 energizes through K1 2 N C contacts speed change delay has reset K1 2 to N C position N O K69 1 contacts close to be gin compressor high speed startup Compressor terminal 4 is energized by contactor K69 terminal L1 T1 Compressor terminal 6 is energized by contactor K69 terminal L2 T2 Compressor terminal 5 is energized by contactor K69 terminal L3 T3 Page 36 241 POWER eg BLOWER AUX HEAT AUX HEAT 2 COOL 2
72. eset the control Activate the compressor by pressing and releasing the override button see illustra Page 9 tion If compressor starts the control is good and should not be replaced Proceed through the troubleshooting flow chart in the Unit Information Manual to locate the source of the lockout If the compressor does not start a problem probably exists elsewhere in the unit Check the unit volt age and proceed through the unit troubleshooting flowchart in the Unit Information Manual LED ON MEANS TSC FAULT CONDITION If the unit will not run and the LED is lit the TSC may be in Safety Dormant Lockout a lockout caused by self test fail ure or high voltage spike To determine if the control is in Safety Dormant Lockout briefly turn off power at the disconnect When power is re stored check the LED If the LED is lit the control is damaged and must be replaced If the LED is not lit the control is probably good and should not be replaced until eliminated by all other checks Confirm this by activating the compressor press and release the override button with thermostat demand present If the compressor starts the control was in safety dormant lockout due to high voltage spike or self test failure and the control should not be re placed If the compressor does not start the control is probably good and the problem is located elsewhere in the unit Proceed through the troubleshooting flowchart to lo cate th
73. g normally resistance through the sensors should be below the trip value shown in table 6 TABLE 6 Compressor Winding Normal Trip Ohms Reset Ohms Temperature Sensor Ohms Temp Rise Temp Fall TSC 6 Copeland Compressor 90 7800 25K 35K 8 4K 10K IMPORTANT Normal resistance values of these com pressors are above 200 ohms but can read 90 ohms during certain ambient temperatures Ohm value below 200 ohms will cause the two speed control to cycle the compressor off and will not allow the compressor to cycle back on until the ohm values are above 200 ohms To prevent this issue the field can install a 150 ohm 1 4 Page 13 watt resistor in series with one of the sensor connections on the two speed control The resistor can be found at elec tronic stores such as Radio Shack Table 7 shows the resistor in series with the control and compressor The control can be checked by comparing the resist ance measured through the sensors to the voltage measured across the sensor terminals with the unit running Table 7shows voltage measured across two speed control terminals S1 and 52 with the compressor running TABLE 7 COMPRESSOR WINDING SENSOR OPERATING RANGE Resistance Through Compressor Winding Temperature Sensor K ohms ohms x 1000 090 200 0 1 70 1 82 6 07 6 48 6 86 7 33 7 55 8 07 8 16 8 72 9 69 10 36 10 34 11 05 10 82 11 57 10 93 11 68 11 35 12 14 11 68 12 48 Voltag
74. hown in section VII Wiring Diagrams and Operation Sequence Q Speed Control Thermostat 555 Early Model 21 1 series units only The indoor thermostat regulates compressor speed when the unit is operating in cooling mode When the unit is oper ating in heating mode speed control thermostat S55 regulates compressor speed 1st stage heating demand from the indoor thermostat ener gizes the compressor Y1 demand Speed control thermostat S55 controls compressor speed Additional heating demand from the indoor thermostat W1 demand energizes the indoor auxiliary heat Speed control thermostat S55 figure 10 is a SPST ther mostat located in the unit control box The control uses a cap tube sensor to monitor the temperature inside the con trol box The cap tube sensor is coiled adjacent to the control SPEED CONTROL THERMOSTAT S55 gt Temperature Sensor ie Cap Tube D p eJ FIGURE 10 S55 continually monitors the temperature inside the control box When control box temperature drops below the con trol setpoint the control closes When the control closes the contacts shunt across Y1 and Y2 inside the unit When heating demand is present and S55 is closed the two speed control electrically sees a high speed demand The compressor operates at high speed until control box warms and S55 opens TABLE 9 Speed Control Thermostat Adjustable Range Factory Setting 40 2 F Min Max Cut In 37 2 F
75. iagnosis before replacing components Be sure to remove all jumper wires and replace all wire con nections and access panels before placing unit back in service TABLE 19 TWO SPEED CONTROL TROUBLESHOOTING FLOWCHART UNIT WILL NOT RUN a IS DIAGNOSTIC LED LIT 0 1 4 gt YES CHECK VOLTAGE ACROSS COMPRES SOR CONTACTOR COILS IS THERE 24 VAC ACROSS HIGH SPEED CONTACTOR COIL THREE PHASE SINGLE IS THERE 24 VAC No across LOW SPEED CONTACTOR COIL IS THERE NOTE Before beginning this troubleshooting pro cedure make sure that 1 primary side of contactor is supplied with line voltage 2 indoor and outdoor transformers are delivering 24vac and 3 line volt age is supplied to compressor terminals when contactors engage CONTROL MAY BE LOCKED OUT TURN POWER OFF AT DISCONNECT FOR 3 SEC IS DIAGNOSTIC LED STILL LIT PHASE T YES NO IS THERE 24 VAC ACROSS LOW SPEED CONTACTOR COIL m YES REPLACE 24 VAC CONTROL ACROSS LOW SPEED CONTACTOR COIL M ves NO NO YES HIGH SPEED AUXILIARY SWITCH IS NOT MAKING PROPERLY REPLACE CONTROL MAY LOCKED OUT 66 CONTACTOR AND REMAKE THERMO HIGH SPEED OR lt YES LOW SPEED CONTACTOR IS FAULTY STAT DEMAND DOES COMPRESSOR START HIGH SPEED OR LOW SPEED CONTACTOR IS FAULTY 1 NORMAL LOCKOUT NO YES TURN OFF UNIT POWER AT DISCONNECT FOR AT LEAST 3 SECONDS TURN POWER ON AND ALLOW 3 SECON
76. ing 7 If the unit is changing from 1st stage to 2nd stage demand the TSC initiates speed change delay and de energizes JP44 8 and JP44 9 to stop all unit operation for 60 5 sec onds After TSC completes the 60 5 second speed change delay or if the unit is starting up in 2nd stage directly from OFF mode TSC checks safety circuits by looking for 24VAC at JP44 7 and by checking resistance through wires con nected to S1 and S2 8 If all safety circuits check out TSC energizes K1 and K69 Compressor begins high speed startup 9 When thermostat demand is satisfied or if thermostat is switched OFF or switched to heating mode all outdoor unit operation stops after a delay of 3 seconds TSC then com pletely resets erase accumulated faults before beginning a 5 minute timed off delay Page 47 SINGLE PHASE HEATING SEQUENCE 10 1st stage demand energizes TB15 Y1 TB15 Y1 energizes TSC and defrost control Defrost control initializes timing sequence NOTE 2nd stage heating demand may be energized di rectly without passing through 1st stage 11 TSC delays 3 seconds before responding to the new com mand Then compressor begins operating at low or high speed depending on the outdoor ambient 12 2nd stage heating demand energizes TB15 Y1 and TB15 W1 TB15 Y1 energizes TSC The compressor con tinues to operate at low or high speed as determined by the outdoor ambient W1 energizes the indoor auxiliary heat relay for 2nd stage heat
77. it may have multiple power supplies AWARNING Improper installation adjustment alteration service maintenance cause property damage person al injury or loss of life Installation and service must be performed by a qualified installer or service agency A WARNING Refrigerant can be harmful if it is inhaled Refrigerant must be used and recovered responsibly Failure to follow this warning may result in person al injury or death Technical Publications Page 1 General z v ee eg 1 Specifications Electrical 2 Beas 3 Unit Components 3 TSC 2 6 TS 3 Control 10 TSC 6 Control 2 2 054 044 des yaw sts 11 Ill Refrigerant System 20 IV Chargirig eee ie eR ec nates 23 Maintenance 2 eee eee 25 VI Miscellaneous 26 VII Wiring Diagrams and Operating Sequence 27 1994 Lennox Industries Inc SPECIFICATIONS HP21 411 HP21 36 230 21 511 21 48 230 HP21 651 21 60 230 HP21 413 HP21 36 233 21 513 21 48 233 21 653 21 60 233 Face area sq ft outside inside Outdoor Coil Tube diameter in No of Rows Fins per inch Diameter in No of Blades Motor hp Cfm Rpm Watts Refrigera
78. it operation for 60 5 seconds Outdoor fan continues to operate After TSC completes the 60 5 second speed change delay or if the unit 2 Relay contacts K10 1 switch to energize the outdoor fan and to de en ergize the crankcase heater 10 If all safety circuits check out TSC energizes K69 Compressor be is starting up in 1st stage directly from OFF mode TSC checks safety gins high speed startup circuits by looking for 24VAC at JP44 7 and by checking resistance 11 When thermostat demand is satisfied or if thermostat is switched OFF through wires connected to 51 and 52 or switched to heating mode all outdoor unit operation stops after a 5 If all safety circuits check out TSC energizes K1 and compressor be delay of 3 seconds TSC then completely resets erase accumulated gins low speed startup faults before beginning a 5 minute timed off delay Page 37 24V POWER amp 9r BLOWER AUX HEAT AUX HEAT 2 COOL 2 REV VALVE COOL HEAT ob 660 BLACK COM O RED 208V ORANGE 230V COM 7 GROUND DESCRIPTION COMPONENT control two speed compressor motor outdoor fan capacitor outdoor fan control defrost comp heater comp jack two speed control X OOO o o LINE VOLTAGE FIELD INSTALLED 2
79. ize compressor operation in response to thermostat demand High speed operation can be ener gized and de energized without passing through low speed The control also contains safety timed off delays and compressor over temperature sensing which pro tect the compressor The control has an external temperature probe to lock out low speed during low tem peratures plus a potentiometer used for setting the low speed lock out temperature The adjustment range is 38 F 3 3 C to 55 F 12 7 x2 F 1 1 C This lock out will occur in both heating and cooling modes A timed off delay in the control prevents short cycling by locking out compressor operation for five minutes after the end of a thermostat demand or after a power failure The control also counts unit fault conditions When the compressor stops due to a safety limit trip or if the com pressor winding temperature becomes too hot the control s internal cycle counter accumulates one fault If three unit faults are counted during the same thermostat demand the control locks out and stops all unit opera tion The control can be reset by breaking and remaking thermostat demand Unit faults are erased when power is interrupted When thermostat demand changes stages compressor operation stops for approximately one minute to allow refrigerant pressure to equalize in the system A manual override button aids servicing and trouble shooting on the control The manual override
80. ks out and the contactor cannot energize If the two speed control is locked out it must be reset before the unit can operate To reset the control break and remake thermostat demand J Service Light Thermostat 554 All units are equipped with a service light thermostat mounted on the compressor discharge line The switch is electrically connected to the service light in the indoor thermostat When compressor discharge line temperature reaches 130 5 F the switch opens If discharge line temperature drops below 110 5 F during unit operation indicating a problem in the system the switch closes If thermostat demand is present when 554 closes the service light is powered to indicate ser vice is needed K Start Capacitor C7 All single phase HP21 units are equipped with a start ca pacitor connected in parallel with the run capacitor The capacitor is switched off by the potential relay when the compressor nears full speed The start capacitor is rated 145 175mfd 330VAC in all single phase units Three phase HP21 units do not use start capacitors L Bleed Resistor R21 All single phase HP21 units are equipped with a bleed re sistor connected in parallel with start capacitor C7 The resistor is used to slowly discharge the capacitor when not in use R21 is a 15 000 ohm 2 watt resistor M Run Capacitor C5 All single phase early model HP21 1 2 3 units use a compressor run capacitor to maximize motor efficiency The run
81. lts which occur during compressor operation and which cause the com pressor to shut off are counted After a fault is counted the control stops unit operation resets and begins a five minute time delay step 2 operation sequence If the control senses a fault at the end of five minutes the unit will not restart If the control counts three faults during the same thermostat de mand the control locks out unit operation A IMPORTANT If the cycle counter counts three faults during the same thermostat demand the control locks out The outdoor unit remains inoperable until thermostat de mand is broken This indicates further troubleshoot ing is needed Though the control can be reset by breaking thermostat demand the unit may remain in operable The high pressure or low pressure condi tions may still exist and must be located and cor rected before the unit can be placed back in service See diagnostic codes to determine problem Page 12 IMPORTANT If the control locks out it can be reset by breaking thermostat demand for about five seconds then re making thermostat demand Also anytime thermo stat demand is removed or power is interrupted the control resets to zero faults A fault occurs when 1 Compressor operation is monitored by high and low pres sure switches These controls are wired in series If either one trips compressor operation is interrupted and one fault is counted The control locks out co
82. mpressor opera tion for a minimum of five minutes when a safety device terminates operation High pressure switch must be reset manually but low pressure switch resets automatically It is likely that the control could count three unit faults from the low pressure switch during a single thermo stat demand since this switch resets automatically However the cycle counter can only count unit faults from the high pressure switch if the reset button is pushed without interrupting thermostat demand 2 On all units using the TSC two speed control terminals 51 52 on the control are connected to temperature sensors thermistors which monitor the temperature of the compressor motor windings The two speed control measures the resistance through the sensors The sen sors increase their resistance as temperature increases for example too much superheat When the resistance through the sensors increases above a preset limit the control stops compressor operation for a minimum of five minutes As the compressor windings cool the re sistance through the sensors drops below the reset limit the control resets automatically and one fault is counted Check sensors by measuring resistance ohms through the sensors with the wires disconnected from the control unit not running The sensor wires are not polarity sensi tive Table 6 shows winding temperature sensor resistance values which will cause the TSC to lock out When unit is operatin
83. nergizes JP44 8 and JP44 9 to stop all unit operation for 60 5 seconds After TSC completes the 60 5 second speed change delay or if the unit is starting up in 2nd stage di rectly from OFF mode TSC checks safety circuits by looking for 24VAC at JP44 7 and by checking resistance through wires connected to S1 and S2 8 If all safety circuits check out TSC energizes K1 and 69 Compres sor begins high speed startup 9 When thermostat demand is satisfied or if thermostat is switched OFF or switched to heating mode all outdoor unit operation stops after a delay of 3 seconds TSC then completely resets erase accumulated faults before beginning a 5 minute timed off delay Page 32 24V POWER BLOWER AUX HEAT AUX HEAT 2 COOL HEAT 2 REV VALVE COOL HEAT BLACK COM RED 208V ORANGE 230V E GROUND DESCRIPTION COMPONENT control two speed compressor 000 00 8606 motor outdoor fan capacitor outdoor fan capacitor compressor capacitor comp hard start control defrost comp X L LO A LI oC L2 9 FOR USE WITH COPPER s CONDUCTORS ONLY REFER TO UNIT RATING PLATE FOR MINIMUM heater comp jack two speed control contactor comp COMMON
84. nt 22 charge furnished Outdoor Fan Vapor line connection sweat LEE Model No 21 36 230 Line voltage data GOhz 208 230 1ph_ 208 230 3ph Ratedloadamps 176 Compressor Powerfactor Locked rotor amps Outdoor Coil Full load amps Fan Motor Locked rotor amps Max fuse or circuit breaker size amps Minimum circuit ampacity 40 ee ees ee ee ee ee Refer to National Electrical Code Manual to determine wire fuse and disconnect size requirements NOTE Extremes of operating range are plus 10 and minus 5 of line voltage Page 2 UNIT CONTROL HP21 ELECTRICAL COMPONENTS LI 0 0 DEFROST CONTROL LIQUID LINE SENSOR REVERSING VALVE AND SOLENOID L1 Tre So SERVICE LIGHT THERMOSTAT S54 CD SS GS CG Ga COMPRESSOR TERMINAL BOX 2 C C 2 6 C HIGH
85. ost control is turned off and cannot initiate defrost TABLE 12 1 DEFROST INITIATION NOTE The symbol AT pronounced delta T is used to represent the difference between liquid line temperature and ambient tem perature The defrost control compares actual AT to a calculated AT to determine when to initiate defrost The defrost control calculates AT by inserting the measured am bient temperature into the following equation You can use the equation to calculate the AT for any ambient temperature AT 0 30 Ambient Temp 15 0 1 Once the defrost control has calculated AT it compares the cal culated value to the actual measured AT When the actual AT ex ceeds the calculated AT defrost is initiated Calculated AT Actual Ambient Control will initiate defrost when measured Temperature F AT exceeds this value 20 S E As long as the liquid line remains above 65 F the defrost control remains turned off If during cooling operation the liquid line drops below 65 F the defrost control will initiate timing sequences monitor liquid line and ambient temper atures and initiate a forced defrost after six hours of compressor run time If defrost is initiated while the unit is in cooling mode the outdoor fan will de energize and the in door auxiliary heat will energize A defrost initiated while the unit is in cooling mode is an indicator that the unit may be operating in low ambient conditions or further trouble
86. outdoor trans former T19 and outdoor unit Crankcase heater is energized through relay K10 1 outdoor fan contacts 2 Transformer T19 provides 24VAC to TSC and contactors K1 and K69 5 The TSC begins a 5 minute delay during which the outdoor unit is not 3 The indoor transformer supplies 24VAC to the indoor unit and the in operational After the 5 minute delay the TSC waits in OFF mode for door thermostat Indoor transformer also provides 24VAC power to 1st stage or 2nd stage demand Page 35 BLACK COM RED 208V ORANGE 230V DESCRIPTION T COMPONE control two speed compressor motor outdoor fan capacitor outdoor fan control defrost comp heater comp jack two speed control contactor comp relay defrost contactor outdoor fan contactor comp 2 speed valve reversing plug two speed control sensor ambient comp thermostat room switch limit hi press comp thermostat crankcase thermostat service light ihermostai speed control transformer cooling control terminal strip low voltage FIGURE 34 I THREE PHASE COMPRESSOR STARTUP LOW SPEED 1 Low speed demand energizes outdoor fan relay K10 and JP44 6 K10 1 switches to energiz
87. perate in low speed for 10 seconds turn off for ten seconds then operate in high speed for 10 seconds The con trol will only go into the test mode if there is no thermostat demand and 5 minutes has elapsed since the unit ran The in door blower does not run during this mode The test mode cannot run more than once every 5 minutes LED LIGHTS Y1 and Y2 lights are connected directly to the inputs from the thermostat They indicate low and high speed demand re spectively The HI and LO lights are connected directly across the contac tor coils They indicate if the high and low speed contactors are energized The HEARTBEAT light is connected to the microcontroller unit MCU It indicates when the control s MCU is operating cor rectly and also when the control is in delay mode It blinks at a rate of four times a second when the MCU is operating proper ly and at a rate of once every two seconds when in the delay mode such as the 1 or 5 minute delay If the LED is continu ously on or off assuming the power is on the MCU is not operating properly and the control needs to be replaced The D1 D2 D4 and D8 see figure 8 diagnostic lights display diagnostic codes to aid in unit troubleshooting Refer to Diag nostic Code Table table 8 Diagnostic Code Display A problem code is normally displayed only for the duration of the error There is one exception During a lock out the code for the problem causing the lock out flashes once
88. perature and the conversion temperature is subcooling subcooling conversion temperature mi nus liquid line temperature The subcooling temperature should approximate the values given in table 17 Add refrigerant to increase subcooling and re move refrigerant to reduce subcooling TABLE 17 Med 2 Sebcooing F HP21 410 510 650 36 48 00 10 3 Page 25 ALL UNITS step 9 9 When unit is properly charged liquid line pressures should approximate those given in table 18 D Oil Charge Factory oil charge in all HP21 series units is 70 fl oz Re placement oil charge is 66 fl oz TABLE 18 NORMAL OPERATING PRESSURES 21 4 21 511 21 6 21 413 21 513 21 653 21 36 230 21 48 233 21 36 230 HP21 36 233 21 48 230 21 36 233 LIQ SUC SUC LIQ suc 10 5 10 5 10 5 7598 175 74 177 182 EXPANSION VALVE ONLY 71059 277 266 HEATING 507 191 40 171 40 ALL UNITS 40 F 184 so 20 227 NOTE Liquid line pressure in heating mode may vary more than 10 PSIG depending on unit matchup All pressures are with unit operating on high speed Indoor return air 80 F for cooling V Maintenance At the beginning of each heating or cooling season the system should be cleaned as follows A Heat Pump Unit 1 Clean and inspect outdoor coil Coil may be flushed with a water hose 2 Rotate fan to check fo
89. qh EAT PUMP SECTION 2B47 528 BIW 529 1 1 9W FIGURE 35 J THREE PHASE COOLING SEQUENCE 6 2nd stage cooling demand energizes TB15 Y1 TB15 Y2 and TB15 O TB15 Y2 energizes TSC terminal JP44 4 15 1 energizes TSC 1 1st stage cooling demand energizes TB15 Y1 and TB15 O TB15 O terminal JP44 6 defrost control terminal HOLD and outdoor fan relay energizes reversing valve 14 15 1 energizes TSC terminal JP44 6 relay K10 and defrost control terminal HOLD Defrost control K10 monitors liquid line temperature and turns off defrost control when liq 7 Relay contacts K10 1 switch to energize the outdoor fan and to de en uid line rises above 65 F ergize the crankcase heater NOTE 2nd stage cooling demand may be energized directly without 8 TSC delays 3 seconds before responding passing through 1st stage 9 If the unit is changing from 1st stage to 2nd stage demand the TSC initiates speed change delay and de energizes JP44 8 and JP44 9 to stop all unit operation for 60 5 seconds After TSC completes the 60 5 3 TSC delays 3 seconds before responding to the new command second speed change delay or if the unit is starting up in 2nd stage di rectly from OFF mode TSC checks safety circuits by looking for 4 If the unit is changing from 2nd stage to 1st stage demand TSC initi 24VAC at JP44 7 and by checking resistance through wires connected ates speed change delay and de energizes JP44 8 and JP44 9 to stop to S1 and S2 all un
90. r frozen bearings or binding Outdoor fan motor is prelubricated and sealed with plugs No further lubrication is required 3 Visually inspect all connecting lines joints and coils for evidence of oil leaks 4 Check all factory and field installed wiring for loose connections 5 Check voltage supply at disconnect unit not operat ing Voltage must be within range listed on unit rating plate If not do not start equipment until the power company has been consulted and the voltage condi tion corrected Check for correct voltage at unit unit operating 6 Check fan motor amp draw Unit nameplate Actual 7 Check compressor amp draw Unit nameplate Actual NOTE If insufficient heating or cooling occurs the unit should be gauged and refrigerant charge checked B Indoor Coil 1 Clean or change filters 2 Check connecting lines joints and coil for evidence of oil leaks 3 Check condensate line and clean if necessary C Indoor Unit 1 Clean or change filters 2 Inspect coil Clean if necessary 3 Rotate blower wheel to check for binding bearings Lennox blower motors are prelubricated and sealed No further lubrication is required Adjust blower speed for cooling The static pressure drop over the coil should be checked to determine the correct blower CFM Refer to Lennox Engineering Handbook for Static Pressure and CFM tables 5 Check all factory and field wiring for loose connec tions 1
91. relay defrost relay hard start contactor comp 2 speed valve reversing plug two speed control resistor bleed Sensor ambient comp thermostat room switch limit hi press comp thermostat crankcase thermostat service light thermostat speed control transformer cooling control CIRCUIT AMPACITY AND MAXIMUM FUSE SIZE TBIS terminal strip low voltage ZA COMPRESSOR MOTOR LENNIXS nc WIRING DIAGRAM THERMALLY PROTECTED ASI 52 DENOTES TERMINAL HI SPEED HEAT PUMP OUTDOOR UNITS DESIGNATIONS sre WINDING LINE VOLTAGE A FIELD INSTALLED LO SPEED 21 511 1 21 651 HP21 411 1P 208 230 60 START LOW VOLTAGE ED FIELD INSTALLED WINDING HEAT PUMP SECT ION 2B46 Al4 O ff TERM BOX Supersedes Form No New Form No 528 dew 529 1 20W Litho U S A FIGURE 31 F SINGLE PHASE HEATING SEQUENCE 1 Speed control thermostat S55 determines whether the compressor is to operate on high or low speed based on outdoor temperature If out door temperature drops below set temperature S55 closes to shunt across Y2 When Y2 is shunted a 2nd stage demand is sent to the two speed control and the compressor runs on high speed If outdoor tem perature rises above set temperature S55 opens and the compres
92. rol is not calibrated a defrost cycle will be initiated after 34 minutes of heating mode com pressor run time The control will terminate the defrost cycle when the coil temperature rises above the preset ter mination temperature or after 14 minutes of defrost operation The termination temperature is factory set at 70 F This setting may be adjusted in the field to 50 F 10 C 60 F 16 C 70 F 21 C or 80 F 27 C The con trol will attempt to self calibrate after this and all other defrost cycle s Calibration success depends on stable system temperatures during the 20 minute calibration peri od If the board fails to calibrate another defrost cycle will be initiated after 34 minutes of heating mode compressor run time Once the defrost board is calibrated it will use de mand defrost logic to initiate a defrost cycle A demand defrost system initiates defrost when the difference be tween the clear coil and frosted coil temperatures exceeds the maximum difference allowed by the control If the control determines an ambient temperature sensor failure and the coil temperature is 35 F 2 C or lower the control will repeatedly initiate a defrost cycle after 34 min utes of heating mode compressor run time If the control determines that the coil temperature sensor has failed the control will not initiate a defrost cycle Test Mode When Y1 is energized and 24V power is being applied to the board a test cycle approxima
93. run windings internally connected in series from ter minals 1 common and 7 The windings form a four pole motor operating at 1800 RPM The four low speed start windings are in series and are connected to terminals 1 common and 8 They are used with the start and run ca pacitors and start relay to start and bring the motor up to speed High speed compressor operation is provided when the run windings are connected in parallel terminals 1 common and 7 to L1 and terminal 2 to L2 The windings form a two pole motor operating at 3600 RPM The two high speed start windings are in series and connected to terminals 1 common and 3 Three Phase Compressor Startup Figure 27 shows the windings of three phase two speed compressors The compressors have two speed three phase induction motors Capacitors are not needed to provide the proper phase and torque characteristics Low speed operation is provided when the motor windings are connected in a series Delta circuit The motor oper ates at 1800 RPM High speed operation is provided when the motor windings are connected in a parallel Delta circuit Normally closed contacts on the low speed contactor provide this connec tion Page 29 SINGLE PHASE MOTOR WINDINGS LOW SPEED MOTOR CEAO TERMINALS COMMON RUN WINDINGS HIGH SPEED START WINDINGS LOW SPEED START WINDINGS START RELAY SINGLE PRASE MOTOR WINDINGS HIGH SPEED MOTOR LEAD TERMINALS RUN WINDINGS
94. sation Thermistor RT3 HP21 units are equipped with an ambient compensation thermistor RT3 attached to the outdoor fan motor bracket The thermistor is connected in series with the heat anticipa tion resistor inside the indoor thermostat The thermistor helps to prevent abnormal droop caused by the anticipation resistors RT3 is a NTC thermistor negative temperature coefficient increase in temperature equals decrease in re sistance As outdoor temperature increases the resistance through RT3 drops As the resistance across RT3 drops the current through the heat anticipation resis tor increases Therefore heat anticipation increases as outdoor temperature decreases RT3 resistance values are shown in table 10 Page 16 TABLE 10 AMBIENT COMPENSATION THERMISTOR Ambient Temperature Resistance Through Sensor ohms a 100 150 T Defrost Control CMC1 The CMC defrost control figure 13 is a solid state control manufactured by Ranco The control provides automatic switching from normal heating operation to defrost mode and back Once in defrost mode the control times the de frost period Defrost time varies dependent on the temperature difference between the liquid line and ambient outdoor temperature The control monitors ambient outdoor air temperature liquid line temperature and total compressor run time to de termine when a defrost cycle is required Two temperature probes are permanently attache
95. shooting is required Defrost Control Components 1 Defrost LED An LED on the circuit board lights to indicate the control is in defrost mode N Ambient Temperature Sensor Ambient sensor red cable is permanently attached to the circuit board The sensing element is attached in side the ambient air port located in lower right corner of compressor compartment see figure 1 Liquid Line Temperature Sensor 1 The blue cable is also permanently attached to the cir cuit board The sensing element is attached to the liquid line next to the expansion valve SOLID STATE DEFROST CONTROL AMBIENT TEMP SENSOR RED LIQUID LINE TEMP SENSOR 24VAC COMMON 24VAC INPUT LED INDICATES DEFROST MODE FIGURE 13 4 24 V Terminal Terminal 24V receives 24VAC from the control trans former in the indoor unit transformer T1 in CB21 series units This terminal powers the control s internal timer relays and temperature probes Terminal 24V is pow ered anytime the indoor transformer is powered 5 DEF RLY Terminal Terminal DEF RLY controls defrost when connected in series with defrost relay coil An internal relay con nected to terminal DEF RLY closes to allow external defrost relay K4 to energize and initiate defrost At the end of defrost period internal relay connected to termi nal DEF RLY opens to de energize external defrost relay 6 Terminal Terminal
96. sor runs on low speed 2 1st stage demand energizes TB15 Y1 15 1 energizes TSC speed control thermostat S55 and defrost control terminal HOLD De frost control initializes timing sequence NOTE 2nd stage heating demand may be energized directly without passing through 1st stage 3 TSC delays 3 seconds before responding to the new command Then Page 33 compressor begins operating at low or high speed as determined by speed control thermostat S55 4 2nd stage heating demand energizes TB15 Y1 and TB15 W1 TB15 Y1 energizes TSC speed control thermostat S55 and defrost control terminal HOLD The compressor continues to operate at low or high speed as determined by speed control thermostat 555 TB15 W1 energizes the indoor auxiliary heat relay for 2nd stage heat 5 Speed control thermostat can open or close during 151 stage or 2nd stage heating operation When S55 opens the compressor runs on low speed When S55 closes the compressor runs on high speed If speed control thermostat S55 opens or closes during compressor op eration TSC initiates speed change delay and stops all unit operation for 60 5 seconds indoor unit continues to operate and if 2nd stage thermostat demand is present auxiliary heat continues operate If all safety circuits check out TSC energizes compressor 24V POWER BLOWER AUX HEAT AUX HEAT 2 COOL HEAT 2 REV VALVE CO
97. strip low voltage AND MAXIMUM FUSE ZA COMPRESSOR MOTOR LENNOX me WIRING DIAGRAM THERMALLY PROTEC AX 51 52 DENOTES TERMINAL HEAT PUMP OUTDOOR UNITS DESIGNATIONS HP21 41I IP NE VOLTAGE 21 511 HP21 651 ELD INSTALLED 208 230 60 W VOLTAGE START D E ALLED WINDING 22 HEAT PUMP SECTION 2B46 BI TERM BOX Supersedes Form No New Form No 528 896W 529 120W Litho U S A FIGURE 28 C SINGLE PHASE STARTING SEQUENCE defrost control CMC1 reversing valve L1 speed control thermostat 555 service light thermostat S54 and ambient thermistor RT3 out 1 Line voltage feeds through L1 L2 to energize outdoor transformer T19 and outdoor unit Crankcase heater is energized through relay K1 auxiliary contacts 2 Transformer T19 provides 24VAC to TSC and contactors K1 and K69 door unit 4 power up 24VAC is fed through JP44 1 and JP44 7 to the TSC The TSC begins a 10 second power up delay 5 The TSC begins a 5 minute delay during which the outdoor unit is not 3 The indoor transformer supplies 24VAC to the indoor unit and the in operational After the 5 minute delay the TSC waits in OFF mode for door thermostat Indoor transformer also provides 24VAC power to 1st stage or 2nd stage demand Page 30 D SINGLE PHASE COMPRESSOR STARTUP LOW SPEED 1 1st stage demand If all safety circuits check out TSC energizes JP44 9 2 Contactor K1 is energized through K69 2 N C contacts K1 2 contacts open to
98. t be opened more than 5 turns Opening or closing the valve does not close the service port To operate the valve fully insert hex wrench into the stem and BACK OUT COUNTER CLOCKWISE UNTIL THE STEM JUST TOUCHES THE RETAINING RING If visual verification of the valve stem reaching the retaining ring is impossible STOP BACKING OUT THE VALVE STEM WHEN THE SLIGHTEST RE SISTANCE IS FELT Because of the small size and therefore the reduced resistance BACK OUT THE LIQUID VALVE 5 TURNS MAXIMUM to prevent going past the retain ing ring If the valve stem is backed out past the retaining ring the O ring can be damaged causing leakage or system pressure could force the valve stem out of the valve body possibly causing personal injury In the event the retaining ring is missing do not at tempt to open the valve Page 23 VAPOR LINE VALVE VALVE BODY HP21 UNITS USE ONE SHOT VAPOR LINE VALVES ONCE OPENED THEY CANNOT BE CLOSED NEW UNIT VALVE CLOSED IC FIGURE 21 After servicing unit replace valve cap finger tight then tighten an additional 1 2 turn 1 2 hex flat Cap must be re placed to prevent leaks L Low Ambient Control Kit Optional The 21 unit will operate satisfactorily down to 45 F 7 C outdoor air temperature without any additional controls For cases where operation of the unit is required at low ambients a Low Ambient Control Kit LB 57113BM 27J00 can be add ed in the field enabling the
99. tat demand is present If no thermostat de mand is present the control resets see unit fault conditions section and returns to step 2 above When thermostat demand is satisfied all unit opera tion stops after a three second delay control de energizes JP44 8 and JP44 9 the control re sets see unit fault conditions section and returns to step two General Operation On power up the control begins a ten seconzd initial delay TSC 6 14 TWO SPEED CONTROL COMPONENTS MODE OPTION 1 ENABLE JUMPER OPTION 2 ENABLE DIAGNOSTIC LEDs SELECTION JUMPERS HEARTBEAT LED MANUAL OVERRIDE BUTTON COMPRESSOR SENSOR CONNECTORS LOW SPEED lock out TEMP ADJUSTMENT OUTDOOR TEMP SENSOR CONNECTOR OPTION 1 CONNECTOR OPTION 2 CONNECTOR SERVICE RELAY CONNECTORS JUMPER D8 D4 D2 D1 LOW SPEED LED HIGH SPEED LED FIGURE 8 TSC 6 A14 MAIN CONTROL PLUG 24VAC POWER INPUT 24VAC COMMON 24VAC SPARE NOT USED 2nd STAGE THERMOSTAT DEMAND THERMOSTAT COMMON C 1st STAGE THERMOSTAT DEMAND 24VAC FROM SAFETY SWITCHES TO INTERNAL CONTACTOR COIL INPUT HIGH SPEED 24VAC OUTPUT JP44 LOW SPEED 24VAC OUTPUT 8 FIGURE 9 Two Speed Control Fault Conditions If the control is in low speed operation high speed operation OFF mode or speed change delay the control counts or ac cumulates faults on an internal cycle counter Only fau
100. ted by shorting the defrost pins together can be terminated by shorting the defrost pins again Otherwise defrost will be terminated as in normal op eration The defrost control continually self tests its internal cir cuits If an internal failure occurs test mode will not function and defrost LED will not light IMPORTANT CONTROL WILL BEGIN TEST MODE ONLY IF NORMAL LOAD IS APPLIED TO CONTROL TERMINALS DO NOT ATTEMPT TO OPERATE OR TEST CONTROL OUT OF UNIT HP21 3 Units HP21 3 units are equipped with a demand defrost system which initiates a defrost cycle based on temperature differ ential and compressor run time The control board includes two permanently attached sensors which monitor coil and outdoor ambient temperatures The coil temperature sen sor is equipped with a spring clip which allows proper positioning on the outdoor coil return bend The ambient temperature sensor is installed in a sampling tube at the base of the unit These sensors must not be detached from the control board and must be replaced as part of the con trol board Do not attempt to cut or splice the temperature sensor wires Page 19 HP21 3 DEFROST CONTROL TERMINATION TEMPERATURE PINS SENSOR CONNECTIONS Figure 15 Operation When the reversing valve is de energized the Y1 circuit is energized and the coil temperature is below 35 F 2 the board logs the compressor run time When the unit is initially started and the cont
101. tely 12 seconds can be initiated by placing the termination temperature jumper across the Test pins If the jumper is applied to the test pins before power is applied or if the jumper is left across the Test pins longer than 5 minutes the control will ignore the test jumper and will revert to normal operation The test jumper will initiate continuous defrost cycles until the test jumper is removed or the 5 minute test period ends SYSTEM A Field Piping Field refrigerant piping consists of liquid and vapor lines from the outdoor unit sweat connections Use Lennox L10 series line sets as shown in table 13 or field fabricated refrigerant lines Refer to the piping section of the Lennox Service Unit Information Manual SUI 803 L9 for proper size type and application of field fabricated lines TABLE 13 EIQUID VAPOR MODEL NO NES LINE LNESETS SETS HP21 410 see sem HP21 36 L10 65 HP21 510 30 ft 50 ft HP21 650 FIELD HP21 60 aen 1 1 8in FABRICATED EXPANSION VALVE DEFROST CONTROL SENSOR ro COOLING CYCLE CIRCUITRY OUTDOOR B Unit Circuitry Conventional heat pump circuitry is used A check valve and expansion valve are used in parallel in the liquid line The check valve is closed when the unit is in heating mode to force refrigerant through the expansion valve Th
102. the compressor runs on high speed If outdoor temperature rises above set temperature S55 opens and the com pressor runs on low speed 2 1st stage demand energizes TB15 Y1 TB15 Y1 energizes TSC speed control thermostat S55 and defrost control terminal HOLD De frost control initializes timing sequence NOTE 2nd stage heating demand may be energized directly without passing through 1st stage 3 TSC delays 3 seconds before responding to the new command Then compressor begins operating at low or high speed as determined by speed control thermostat S55 4 2nd stage heating demand energizes TB15 Y1 and TB15 W1 TB15 Y1 energizes TSC speed control thermostat S55 and defrost control terminal HOLD The compressor continues to operate at low or high speed as determined by speed control thermostat 555 TB15 W1 energizes the indoor auxiliary heat relay for 2nd stage heat 5 Speed control thermostat can open or close during 1st stage or 2nd stage heating operation When S55 opens the compressor runs on low speed When S55 closes the compressor runs on high speed If speed control thermostat S55 opens or closes during compressor op eration TSC initiates speed change delay and stops all unit operation for 60 5 seconds indoor unit continues to operate and if 2nd stage thermostat demand is present auxiliary heat continues operate If all safety circuits check out TSC energizes compressor Page 38 24V TBIS R
103. the sensors should be below the trip value shown in table 3 The control can be checked by comparing the resist ance measured through the sensors to the voltage measured across the sensor terminals with the unit running Table 4 shows voltage measured across two speed control terminals S1 and 52 with the compressor running Page 8 TABLE 3 Compressor Winding Trip Ohms Reset Ohms Temperature Sensor Temp Rise Temp Fall TSC 2 Bristol or Copeland Compressor 25K to 35K 8 4K to 10K Two Speed Control Manual Override The manual override button is designed to be an aid in ser vicing and troubleshooting the control or the unit When the button is pushed and then released the control bypasses the five minute override delay TABLE 4 COMPRESSOR WINDING SENSOR OPERATING RANGE Resistance Through Voltage Across TSC Ter Compressor Winding minals S1 and S2 with Temperature Sensor Unit Running K ohms ohms x 1000 DC Volts 15 DC volts Measured with unit running Do not use the override button for eleven seconds after power up If the button is pushed during the ten second power up delay the button has no effect The control com pletes the five minute delay LED OFF MAY MEAN UNIT FAULT CONDITION If the unit will not run and the LED is not lit a unit lockout condition is indicated Breaking and remaking thermostat demand will r
104. unit to operate properly down to 30 F 1 C Included in the kit are the low ambient relay K58 and the low pressure switch S11 IV CHARGING The unit is factory charged with the amount of R 22 refrig erant indicated on the unit rating plate This charge as shown in figure 14 is based on a matching indoor coil and outdoor coil with 15 feet of line set TABLE 14 Model Refrigerant Charge R 22 HP21 410 36 13 Ibs 8 oz HP21 510 48 15 Ibs 8 oz 21 650 60 i9lbs2oz For varying lengths of line set refer to table 15 for refriger ant charge adjustment A blank space is provided on the unit rating plate to list actual field charge TABLE 15 VALVE OPEN FRANGIBLE PLUG Ounces per foot LINE SET DIAMETER ar adjust from 15 ft Vapor m dem 19mm 10mm 15ml 7 8 in 3 8 in 3 4 ounce 22mm 10mm 21ml 29mm 10mm 21ml If line length is greater than 15 feet add this amount If line length is less than 15 feet subtract this amount A Leak Testing 1 Attach gauge manifold and connect a drum of dry nitro gen to center port of gauge manifold CAUTION WHEN USING DRY NITROGEN PRES SURE REDUCING REGULATOR MUST BE USED TO PREVENT EXCESSIVE PRESSURE IN GAUGE MANIFOLD CONNECTING HOSES AND WITHIN THE SYSTEM REGULATOR SETTING MUST NOT EXCEED 150 PSIG 1034 KPA 2 Open high pressure valve on gauge manifold and pres surize line
105. zed directly by contactor K1 terminal L1 T1 Compressor termi nal 7 is energized by contactor K1 terminal L1 T1 through contactor K69 terminal 11 1 9 Outdoor fan B4 is energized through relay K4 2 when contactor K1 contacts L1 T1 and L2 T2 close 10 As the compressor nears full speed potential relay K31 energizes and K31 contacts open to de energize start capacitor C7 1 SE HI SPEED START WINDING LINE VOLTAGE aAA FIELD INSTALLED LO SPEED START WINDING 21 32 l 7 TERM BOX 40 O LOW VOLTAGE FIELD INSTALLED DESCRIPTION COMPONENT control two speed compressor motor outdoor fan capacitor outdoor fan capacitor compressor capacitor comp hard start nirol defrost mp heater comp jack two speed control ontactor comp relay defrost relay hard ar contactor comp 2 speed valve reversing plug two speed control resistor bleed sensor ambient comp thermostat room switch limit hi press comp ihermostat crankcase thermostat service light thermostat speed control transformer cooling contro terminal strip low voltage FIGURE 29 Page 31 24V POWER TBIS R BLOWER mm HEAT AUX HEAT 2 COOL HEAT 2 REV

Lennox HP21 - Heat Pumps

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